Ernok, The Gluttony Sin

Firststrike
Landfall - Whenever a land enters the battlefield
under your control, Ernok, The Gluttony Sin
gets +1/+0 until end of turn.
{1}{g/w}{g/w}: Target creature you control gains
flying until end of turn. If this is the third time
this ability has been activated this turn, sacrifice
Ernok at your next end step.