Breeder's Toxel .

This Pokémon can be received from the Breeder inside Route 5's Daycare, which players' have access to after defeating Milo.

Toxel evolves into Toxtricity, which has 2 forms.
It will have the Amped form, if it's nature is Hardy, Brave, Adamant, Naughty, Docile, Impish, Lax, Hasty, Jolly, Naive, Rash, Sassy, or Quirky.
It will have the Low Key form, if it's nature is Lonely, Bold, Relaxed, Timid, Serious, Modest, Mild, Quiet, Bashful, Calm, Gentle, or Careful.