Muaka, Dune Prowler

Muaka, Dune Prowler enters the battlefield with
an infection counter on it.
Muaka, Dune Prowler gets -1/-1 for each counter
on it.
When Muaka, Dune Prowler enters the
battlefield and when you take combat damage, it
fights target creature you don't control.
(Creatures with infection counters can't block.
When this creature takes damage, remove an
infection counter from it.)