The Ur-Dreadmaw

Trample

If The Ur-Dreadmaw is your commander, you may
have any number of cards named Colossal
Dreadmaw in your library.

Whenever a nonmodified creature you control
named Colossal Dreadmaw attacks, you may place a
permanent from your hand named Colossal
Dreadmaw onto the battlefield tapped and
attacking with a haste counter.