Warping Wurm

Mana cost: {2}{G}{U}

Creature — Wurm

Phasing (This phases in or out before you untap during each of your untap steps. While it's phased out, it's treated as though it doesn't exist.) At the beginning of your upkeep, this creature phases out unless you pay {2}{G}{U}. Whenever this creature phases in, put a +1/+1 counter on it.