theSLAYER

In Pokemon Diamond, Pearl & Platinum, when the player brings Regirock, Regice & Registeel to the immobile statue at the lowest level of the Snowpoint Temple, the statue will reanimate and reveal its true identity: Regigigas.
     Species   Regigigas   Nickname   (default, save lang)   OT   (recipient)   TID   (recipient)   Distribution   In-Game Encounter   Location   Snowpoint Temple   Dates   (Various)   PID   Chance of Shiny   Games   DPPt                                                                Lv. 1    Nature   Random   Ability   Slow Start   Item   None    Moves       Dizzy Punch   Knock Off   Confuse Ray   Foresight
  Format Ver.1.0.6-2, Post Updated Date:20180510_1727

In Pokemon Diamond, Pearl and Platinum Versions, holds the event locations Seabreak Path and Flower Paradise.
After using the event item Oak's Letter, Route 224 gains an extension (Seabreak Path) which will lead the player to Flower Paradise.
There, players will be able to challenge (and potentially capture) a level 30 wild Shaymin.
The Oak's Letter event key item was only distributed to Pokemon Platinum.
     Species   Shaymin   Nickname   (default, save lang)   OT   (recipient)   TID   (recipient)   Distribution   In-Game Encounter   Location   Flower Paradise   Dates   (Various Dates)   PID   Chance of Shiny   Games   Platinum                                                                Lv. 30    Nature   Random   Ability   Natural Cure   Item   None    Moves       Growth   Magical Leaf   Leech Seed   Synthesis
  Format Ver.1.0.6-2, Post Updated Date:20180508_0038

In Pokemon Diamond, Pearl and Platinum Versions, holds the event location Newmoon Island.

After using the event item Member Card, players gain access to the defunct Harbor Inn in Canalave City,
falls asleep enters a "dream state", dreaming of an encounter with Darkrai at Newmoon Island.
Darkrai can be captured in the "dream". If defeated or fled from, it can be re-battled again in the actual location.
The Member Card event key item was only distributed to Pokemon Platinum.
     Species   Darkrai   Nickname   (default, save lang)   OT   (recipient)   TID   (recipient)   Distribution   In-Game Encounter   Location   Newmoon Island   Dates   (Various)   PID   Chance of Shiny   Games   Platinum                                                                Lv. 50    Nature   Random   Ability   Bad Dreams   Item   None    Moves       Hypnosis   Feint Attack   Nightmare   Double Team
  Format Ver.1.0.6-2, Post Updated Date:20180508_0013

The monster that resides in the furthest reaches of the unknown dungeon.
     Species   Mewtwo   Nickname   (default, save lang)   OT   (recipient)   TID   (recipient)   Distribution   In-Game Encounter   Location   Cerulean Cave   Dates   (Various)   PID   Chance of Shiny   Games   HeartGold & SoulSilver                                                                Lv. 70    Nature   Random   Ability   Pressure   Item   None    Moves       Psycho Cut   Amnesia   Power Swap   Guard Swap   Format Ver.1.0.6-2, Post Updated Date:20180507_1927

In Kanto, a Snorlax blocks the entrance to Diglett's Cave, as well as the path towards to Route 11.
If defeated here, it'll appear again at Route 12 after the player enters the Hall of Fame again.
     Species   Snorlax   Nickname   (default, save lang)   OT   (recipient)   TID   (recipient)   Distribution   In-Game Encounter   Location   Route 11 / Route 12   Dates   (Various)   PID   Chance of Shiny   Games   Heart Gold / Soul Silver                                                                Lv. 50    Nature   Random   Ability   Immunity or Thick Fat   Item   Leftovers    Moves       Block   Rollout   Crunch   Giga Impact
  Format Ver.1.0.6-2, Post Updated Date:20180507_1208

After players complete the puzzle at the Sealed Chamber, the entrances to Desert Ruins, Island Cave and Ancient Tomb will become unsealed.
After entering the chamber, another puzzle will come between the player and the golem residing within.
In order to gain access to the rear chamber, the player has to read the Braille on the wall,
then proceed to the center of the room and have a Pokemon in the party use Fly (HM).
     Species   Registeel   Nickname   (default, save lang)   OT   (recipient)   TID   (recipient)   Distribution   In-Game Encounter   Location   Ancient Tomb   Dates   (Various)   PID   Chance of Shiny   Games   ORAS                                                                Lv. 40    Nature   Random   Ability   Clear Body   Item   None    Moves   (ITALIC means Relearnable)   Curse   Ancient Power   Iron Defense   Amnesia
  Format Ver.1.0.6-2, Post Updated Date:20180505_2215

In Pokemon Omega Ruby & Alpha Sapphire, after players complete the puzzle at the Sealed Chamber, the entrances to Desert Ruins, Island Cave and Ancient Tomb will become unsealed.

In order to encounter Regigigas, the player has to bring Regirock, Registeel and Regice to the Island Cave, in daytime.
Additionally, the Regice has to be nicknamed, and must carry an frozen-affiliated item, namely CasteliaCone, Snowball, or Never-Melt Ice.
     Species   Regigigas   Nickname   (default, save lang)   OT   (recipient)   TID   (recipient)   Distribution   In-Game Encounter   Location   Island Cave   Dates   (Various)   PID   Chance of Shiny   Games   ORAS                                                                Lv. 50    Nature   Random   Ability   Slow Start   Item   None    Moves   (ITALIC means Relearnable)   Foresight   Revenge   Wide Guard   Zen Headbutt
  Format Ver.1.0.6-2, Post Updated Date:20180505_2221

After players complete the puzzle at the Sealed Chamber, the entrances to Desert Ruins, Island Cave and Ancient Tomb will become unsealed.
After entering the chamber, another puzzle will come between the player and the golem residing within.
In order to gain access to the rear chamber, the player has to read the Braille on the wall, and wait a full 2 minutes.
     Species   Regice   Nickname   (default, save lang)   OT   (recipient)   TID   (recipient)   Distribution   In-Game Encounter   Location   Island Cave   Dates   (Various)   PID   Chance of Shiny   Games   ORAS                                                                Lv. 40    Nature   Random   Ability   Clear Body   Item   None    Moves   (ITALIC means Relearnable)   Bulldoze   Curse   Ancient Power   Amnesia
  Format Ver.1.0.6-2, Post Updated Date:20180505_2209

After players complete the puzzle at the Sealed Chamber, the entrances to Desert Ruins, Island Cave and Ancient Tomb will become unsealed.
After entering the chamber, another puzzle will come between the player and the golem residing within.
In order to gain access to the rear chamber, the player has to read the Braille on the wall,
Use the D-pad to go right twice, and go down twice, and finally have a Pokemon in the party use Strength (HM).
     Species   Regirock   Nickname   (default, save lang)   OT   (recipient)   TID   (recipient)   Distribution   In-Game Encounter   Location   Desert Ruins   Dates   (Various)   PID   Chance of Shiny   Games   ORAS                                                                Lv. 40    Nature   Random   Ability   Clear Body   Item   None    Moves   (ITALIC means Relearnable)   Bulldoze   Curse   Ancient Power   Iron Defense
  Format Ver.1.0.6-2, Post Updated Date:20180505_2213

Species   Uxie   Nickname   (default, save lang)   OT   (recipient)   TID   (recipient)   Distribution   In-Game Encounter   Location   Nameless Cavern   Dates   (Various Dates)   PID   Chance of Shiny   Games   ORAS                                                                Lv. 50    Nature   Random   Ability   Levitate   Item   None    Moves   (ITALIC means Relearnable)   Yawn   Future Sight   Amnesia   Extrasensory
  Format Ver.1.0.6-2, Post Updated Date:20180506_0538

Species   Mesprit   Nickname   (default, save lang)   OT   (recipient)   TID   (recipient)   Distribution   In-Game Encounter   Location   Nameless Cavern   Dates   (Various)   PID   Chance of Shiny   Games   ORAS                                                                Lv. 50    Nature   Random   Ability   Levitate   Item   None    Moves   (ITALIC means Relearnable)   Lucky Chant   Future Sight   Charm   Extrasensory
  Format Ver.1.0.6-2, Post Updated Date:20180506_0536

Species   Azelf   Nickname   (default, save lang)   OT   (recipient)   TID   (recipient)   Distribution   In-Game Encounter   Location   Nameless Cavern   Dates   (Various)   PID   Chance of Shiny   Games   ORAS                                                                Lv. 50    Nature   Random   Ability   Levitate   Item   None    Moves   (ITALIC means Relearnable)   Uproar   Future Sight   Nasty Plot   Extrasensory
  Format Ver.1.0.6-2, Post Updated Date:20180506_0534

In Pokemon Omega Ruby & Alpha Sapphire, after main storyline involving the Primal Groudon or Primal Kyogre,
Heatran can be found in the hoop portal at the end of cave.
     Species   Heatran   Nickname   (default, save lang)   OT   (recipient)   TID   (recipient)   Distribution   In-Game Encounter   Location   Scorched Slab   Dates   (Various)   PID   Chance of Shiny   Games   ORAS                                                                Lv. 50    Nature   Random   Ability   Flash Fire   Item   None    Moves   (ITALIC means Relearnable)   Metal Sound   Crunch   Scary Face   Lava Plume
  Format Ver.1.0.6-2, Post Updated Date:20180505_2125

In Pokemon Omega Ruby & Alpha Sapphire, the Crescent Isle is one of out the thirty three daily random mirage spots that may appear.
It is possible to receive another 10 mirage spots from StreetPass, and it is possible to receive this mirage spot using this method.
     Species   Cresselia   Nickname   (default, save lang)   OT   (recipient)   TID   (recipient)   Distribution   In-Game Encounter   Location   Crescent Isle   Dates   (Various)   PID   Chance of Shiny   Games   ORAS                                                                Lv. 50    Nature   Random   Ability   Levitate   Item   None    Moves   (ITALIC means Relearnable)   Mist   Aurora Beam   Future Sight   Slash
  Format Ver.1.0.6-2, Post Updated Date:20180505_2019

In Pokemon Omega Ruby & Alpha Sapphire, when the player is soaring in the sky with 3 maxed effort values Pokemon in their party, the Pathless Plain mirage spot will appear.
When the player interacts with the hoop towards the end of the Pathless Plain, a battle will be initiated.
Virizion can be encountered on Mondays and Thursdays, Terrakion can be encountered on Tuesdays and Saturdays, and Cobalion can be encountered on Wednesdays, Fridays and Sundays.
     Species   Virizion   Nickname   (default, save lang)   OT   (recipient)   TID   (recipient)   Distribution   In-Game Encounter   Location   Pathless Plain   Dates   (Various)   PID   Chance of Shiny   Games   ORAS                                                                Lv. 50    Nature   Random   Ability   Justified   Item   None    Moves   (ITALIC means Relearnable)   Retaliate   Giga Drain   Sacred Sword   Swords Dance
  Format Ver.1.0.6-2, Post Updated Date:20180505_2016

In Pokemon Omega Ruby & Alpha Sapphire, when the player is soaring in the sky with 3 maxed effort values Pokemon in their party, the Pathless Plain mirage spot will appear.
When the player interacts with the hoop towards the end of the Pathless Plain, a battle will be initiated.
Virizion can be encountered on Mondays and Thursdays, Terrakion can be encountered on Tuesdays and Saturdays, and Cobalion can be encountered on Wednesdays, Fridays and Sundays.
     Species   Terrakion   Nickname   (default, save lang)   OT   (recipient)   TID   (recipient)   Distribution   In-Game Encounter   Location   Pathless Plain   Dates   (Various)   PID   Chance of Shiny   Games   ORAS                                                                Lv. 50    Nature   Random   Ability   Justified   Item   None    Moves   (ITALIC means Relearnable)   Retaliate   Rock Slide   Sacred Sword   Swords Dance
  Format Ver.1.0.6-2, Post Updated Date:20180505_2010

In Pokemon Omega Ruby & Alpha Sapphire, when the player is soaring in the sky with 3 maxed effort values Pokemon in their party, the Pathless Plain mirage spot will appear.
When the player interacts with the hoop towards the end of the Pathless Plain, a battle will be initiated.
Virizion can be encountered on Mondays and Thursdays, Terrakion can be encountered on Tuesdays and Saturdays, and Cobalion can be encountered on Wednesdays, Fridays and Sundays.
     Species   Cobalion   Nickname   (default, save lang)   OT   (recipient)   TID   (recipient)   Distribution   In-Game Encounter   Location   Pathless Plain   Dates   (Various)   PID   Chance of Shiny   Games   ORAS                                                                Lv. 50    Nature   Random   Ability   Justified   Item   None    Moves   (ITALIC means Relearnable)   Retaliate   Iron Head   Sacred Sword   Swords Dance
  Format Ver.1.0.6-2, Post Updated Date:20180505_2002

In Pokemon Omega Ruby & Alpha Sapphire, after the player defeats the Elite Four for the first time, the player is able to complete the post-game quest: Delta Episode.
The final act of the arc, the player has to capture Rayquaza, and ride Mega Rayquaza into space, with the aim to destroy a meteorite that is hurdling down to Earth, threatening to decimate the Hoenn region.
This Pokemon has to be captured, in order to progress through the storyline.
If it was defeated or ran from, it would still be there, awaiting the player to begin the encounter again.
Additionally, even if the player attempts to fill all the slots in their PC, Box 31 was hidden from usage,
and is only unlocked after this Pokemon's capture.
     Species   Rayquaza   Nickname   (default, save lang)   OT   (recipient)   TID   (recipient)   Distribution   In-Game Encounter   Location   Sky Pillar   Dates   (Various)   PID   Cannot Be Shiny   Games   ORAS                                                                Lv. 70    Nature   Random   Ability   Air Lock   Item   None    Moves   (ITALIC means Relearnable)   Extreme Speed   Dragon Pulse   Dragon Dance   Dragon Ascent
  Format Ver.1.0.6-2, Post Updated Date:20180504_2055

In Pokemon Omega Ruby & Alpha Sapphire, when the player is soaring in the sky with Zekrom & Reshiram in their party,
the Gnarled Den mirage spot will appear.

When the player interacts with the hoop in the Gnarled Den, Kyurem will appear.
     Species   Kyurem   Nickname   (default, save lang)   OT   (recipient)   TID   (recipient)   Distribution   In-Game Encounter   Location   Gnarled Den   Dates   (Various)   PID   Chance of Shiny   Games   ORAS                                                                Lv. 50    Nature   Random   Ability   Pressure   Item   None    Moves   (ITALIC means Relearnable)   Dragon Breath   Slash   Scary Face   Glaciate
  Format Ver.1.0.6-2, Post Updated Date:20180504_2004

In Pokemon Alpha Sapphire, when the player is soaring in the sky with a Level 100 Pokemon in their party,
the Fabled Cave mirage spot will appear.

When the player interacts with the hoop in the Fabled Cave, Zekrom will appear.
This also marks the first time Zekrom being able to be encountered shiny.
     Species   Zekrom   Nickname   (default, save lang)   OT   (recipient)   TID   (recipient)   Distribution   In-Game Encounter   Location   Fabled Cave   Dates   (Various)   PID   Chance of Shiny   Games   AS                                                                Lv. 50    Nature   Random   Ability   Teravolt   Item   None    Moves   (ITALIC means Relearnable)   Dragon Breath   Slash   Zen Headbutt   Fusion Bolt
  Format Ver.1.0.6-2, Post Updated Date:20180504_1957

In Pokemon Omega Ruby & Alpha Sapphire, when the player is soaring in the sky with Dialga and Palkia in their party,
a rift in space-time will appear over Hoenn.
When the player interacts with the rift, Giratina is encountered.
     Species   Giratina   Nickname   (default, save lang)   OT   (recipient)   TID   (recipient)   Distribution   In-Game Encounter   Location   Soaring in the sky   Dates   (Various)   PID   Chance of Shiny   Games   ORAS                                                                Lv. 50    Nature   Random   Ability   Pressure   Item   None    Moves   (ITALIC means Relearnable)   Aura Sphere   Shadow Claw   Shadow Force   Hex
  Format Ver.1.0.6-2, Post Updated Date:20180504_1955

In Pokemon Alpha Sapphire, when the player is soaring in the sky with Azelf, Mesprit and Uxie in their party,
a rift in space-time will appear over Hoenn.
When the player interacts with the rift, Dialga is encountered.
     Species   Dialga   Nickname   (default, save lang)   OT   (recipient)   TID   (recipient)   Distribution   In-Game Encounter   Location   Soaring in the sky   Dates   (Various)   PID   Chance of Shiny   Games   AS                                                                Lv. 50    Nature   Random   Ability   Pressure   Item   None    Moves   (ITALIC means Relearnable)   Aura Sphere   Iron Tail   Roar of Time   Flash Cannon
  Format Ver.1.0.6-2, Post Updated Date:20180504_1951

In Pokemon Alpha Sapphire, after main storyline involving the Primal Kyogre, the player will receive the Tidal Bell key item after speaking to Captain Stern in Slateport City.
Players can then head to the Sea Mauville to encounter Lugia.
     Species   Lugia   Nickname   (default, save lang)   OT   (recipient)   TID   (recipient)   Distribution   In-Game Encounter   Location   Sea Mauville   Dates   (Various)   PID   Chance of Shiny   Games   AS                                                                Lv. 50    Nature   Random   Ability   Pressure   Item   None    Moves   (ITALIC means Relearnable)   Rain Dance   Hydro Pump   Aeroblast   Punishment
  Format Ver.1.0.6-2, Post Updated Date:20180504_1936

The Trackless Forest is a mirage spot that appears when the player is soaring in the sky, with Lugia or Ho-Oh in their party.
     Species   Suicune   Nickname   (default, save lang)   OT   (recipient)   TID   (recipient)   Distribution   In-Game Encounter   Location   Trackless Forest   Dates   (Various)   PID   Chance of Shiny   Games   ORAS                                                                Lv. 50    Nature   Random   Ability   Pressure   Item   None    Moves   (ITALIC means Relearnable)   Aurora Beam   Mist   Mirror Coat   Ice Fang
  Format Ver.1.0.6-2, Post Updated Date:20180504_1931

The Trackless Forest is a mirage spot that appears when the player is soaring in the sky, with Lugia or Ho-Oh in their party.
     Species   Entei   Nickname   (default, save lang)   OT   (recipient)   TID   (recipient)   Distribution   In-Game Encounter   Location   Trackless Forest   Dates   (Various)   PID   Chance of Shiny   Games   ORAS                                                                Lv. 50    Nature   Random   Ability   Pressure   Item   None    Moves   (ITALIC means Relearnable)   Stomp   Flamethrower   Swagger   Fire Fang
  Format Ver.1.0.6-2, Post Updated Date:20180504_1929