Twin Blazed Berserker

Twin Blazed Berserker enters the battlefield with
a +1/+1 counter on it.
When Twin Blazed Berserker enters the battlefield, you may have it gain haste until
end of turn. If you do, at the beginning of your
next end step, Exhaust 1.(Remove a +1/+1 counter
from this creature.)
They say a candle that burns twice as hot lasts half as
long and these fledglings burn at both ends.