The Titleholder

Whenever a creature you control causes a creature
an opponent controls to die, you may attach The Titleholder to that creature.
Equipped creature gets +2/+2, has menace, and
has "When a permanent with a bounty counter
on it an opponent controls is put into a graveyard,
put a 1+/+1 counter on this creature, then you
may draw two cards, then discard two cards. "