Artifact, 2 (2)
Uncommon
Whenever a player casts a green spell, you may gain 1 life.
A wurm knows nothing of deception. If it opens its mouth, it plans to eat you.
Illus. Alan Pollack

10/1/2009: The ability triggers whenever any player, not just you, casts a green spell.
10/1/2009: If a player casts a green spell, Wurm's Tooth's ability triggers and is put on the stack on top of that spell. Wurm's Tooth's ability will resolve (causing you to gain 1 life) before the spell does.
Legal in Vintage (Type 1)
Legal in Legacy (Type 1.5)
Legal in Extended (Type 1.X)
Legal in Classic (MTGO)
Legal in Commander
Legal in Modern