You get MEOW MIX the Meowth! It's a bit of a kleptomaniac, so its ability must be Pickup. You can never give it an item, because it wouldn't be able to pick up things. It's afraid of being paralyzed by Electric types, as it would be more difficult to pick up things, so you can't use it against Electric-type Pokémon until it evolves. It seeks to find its hidden power, so it must learn and keep Hidden Power to evolve. After evolution, its ability will no longer be Pickup. It will be Limber, freeing it from the Electric-type restriction as it can no longer be paralyzed.
I am feeling so original today!
We're by no means setting a precedent.