Sturdy Hatchling [Eventide]

Sturdy Hatchling enters the battlefield with four -1/-1 counters on it. {G/U}: Sturdy Hatchling gains shroud until end of turn. (It can't be the target of spells or abilities.) 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.