Tauros

Tauros attacks each turn if able. If it does, defending player's creatures get -1/-0 until end of turn.
Trample, protection from Spirits,
Rampage 2 (Whenever this creature becomes blocked,
it gets +2/+2 until end of turn for each creature
blocking it beyond the first.)
You may exert Tauros as it attacks. If you do,
it gets +X/+0 until end of turn, where X is it's
power. (An exerted creature won't untap during
your next untap step.)