FusionDex

It's believed that Deiki is able to open many types of locks, but to understand how to unlock one, they first need to headbutt it. This almost always breaks the lock, invalidating the need for a key.

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. They cannot see, so they tackle and bite to learn about their surroundings.