FusionDex

Klefxys can create a key in any shape it desires out of its body. It's sought after by powerful crime organizations like Team Rocket as a way to get into any building using its keys.

A Pokémon that mutated from an extraterrestrial virus exposed to a laser beam. It never lets go of a key that it likes, so people give it the keys to vaults and safes as a way to prevent crime.