Ravenous Rage Fiend

Haste, feast - whenever a creature with feast
destroys a creature with less toughness, it adds
the destroyed creatures toughness to its own until
it destroys and replaces it with another creature.
Double-strike whenever this creature attacks.
Desperate thieves and criminals would travel through
the forbidden lands since they were devoid of the law.
Problem was, something much worse lived there.