FusionDex

The giant keys Klefwrath hold a value only known to them. Any attempt to remove these keys from them ends in a brutal beatdown. They were prized for their protective natures and were given keys to vaults and doors of the rich and royalty in the past.

Its highly developed muscles never grow fatigued, however much it exercises. 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.