Creature - Elemental 6/6, 3{G/U} (4) Sturdy Hatchling enters the battlefield with four -1/-1 counters on it. {G/U}: Sturdy Hatchling gains shroud until end of turn. Whenever you cast a green spell, remove a -1/-1 counter from Sturdy Hatchling. Whenever you cast a blue spell, remove a -1/-1 counter from Sturdy Hatchling.1
Illus. Darrell Riche
8/1/2008: If you cast a spell that's both of the listed colors, both abilities will trigger. You'll remove a total of two -1/-1 counters from the Hatchling.
8/1/2008: If there are no -1/-1 counters on it when the triggered ability resolves, the ability does nothing. There is no penalty for not being able to remove a counter.