Chasm Predator

Infect (This creature deals damage to creatures in the
form of -1/-1 counters and to players in the form of
poison counters.)
Skulk (This creature can't be blocked by creatures
with greater power.)
{p/u}{p/u}: Chasm Predator gets -1/+1 until end of
turn. ({p/u} can be paid with either {u} or 2 life.)