Any chance these are authentic JEREMY pokemon? Sandshrew, Slowpoke, and Shellder in particular. There isn't a lot of information available about them on bulbapedia and other references. I cross-referenced all of them with bulbapedia and this neoseeker page that seems to have more information regarding Sandshrew, Slowpoke, and Shellder. Neoseeker doesn't list IVs or met location whereas bulbapedia does.
Ekans information matched bulbapedia but neoseeker listed it as level 15 023 - EKANS - AC32E9D9B217.pk3
Sandshrew information matches neoseeker but level, met location, moveset, nature, and IVs are all missing on bulba 027 - SANDSHREW - 680B215F6980.pk3
Vulpix information matches neatly with both references 037 - VULPIX - F1DE65A0DE74.pk3
Oddish information also matches both references 043 - ODDISH - B8FFA23E7080.pk3
Psyduck information matches bulbapedia but the TID is listed differently in addition to Psyduck's Screech being absent from the moveset on neoseeker 054 - PSYDUCK - 297BEBAEB6DA.pk3
Growlithe information matches bulbapedia but she's listed as Tauros and has a docile nature according to neoseeker 058 - GROWLITHE - A7DCD6A3173E.pk3
Machamp information matches both references 068 - MACHAMP - 481FF48C3744.pk3
Slowpoke information matches neoseeker with the exception of her ability and moveset, but level, met location, moveset, nature, and IVs are all missing on bulba 079 - SLOWPOKE - 29345A06444B.pk3
Shellder information mostly matches neoseeker (fourth move listed as bubblebeam, Shellder knows aurora beam), but level, met location, moveset, nature, and IVs are all also missing on bulba 090 - SHELLDER - DB340CAC3758.pk3
I also have a Gengar, Staryu, and Tauros but in pk4 format. I can share those as well if they can be used to verify the legitimacy of these. I managed to get these from a buddy who had recently been gifted his older sister's collection of pokemon games. I got his permission to look through his boxes and pick out some pokemon I want. Now I just want to know if it's too good to be true.