Oil-Drinker Hydra

Trample
Immunity (This creature can't get -1/-1
counters.)
Tether (This creature can't be exiled or returned
to its owner's hand.)
Oil-Drinker Hydra enters the battlefield with {x} +1/+1 counters on it.
{x}{b/g}{u/b}{g/u}{t}, Remove {x} oil counters from permanents an opponent controls: Put {x} +1/+1 counters on Oil-Drinker Hydra.