Uzor, the Irrefutable

: Whenever a creature you control mutates, put a trample counter on it and put a loyalty counter on Uzor.
-2: Create a colorless Spell Tomb artifact token with "sacrifice this artifact: you gain 4 life."
-12: Destroy all non-mutated creatures. Put a -1/-1 counter on each creature that has mutated for each time it has mutated.