The Legendary Bat

Begin the game with this card revealed.
Eminence-When a nontoken creature
enters the battlefield under your control, it
becomes Legendary in addition to its type
and gains "Enrage-when this creature
is dealt damage, you gain life equal this
creature's toughness and you may draw a
card."
Only creatures you control assign combat
equal to its toughness or power, whichever
is greater.