Creature — Wurm 4/4, 2G (3)
Uncommon
When Fallow Wurm enters the battlefield, sacrifice it unless you discard a land card.
The wurm's wake
—Elvish expression meaning
"ruined crops"
Illus. Stephen L. Walsh

4/1/2008: When the ability resolves, you choose whether to sacrifice the creature or perform the other action. If you can’t perform the other action, then you must sacrifice the creature.
4/1/2008: If the creature is no longer on the battlefield when the ability resolves, you may still perform the action if you want.
Legal in Vintage (Type 1)
Legal in Legacy (Type 1.5)
Legal in Classic (MTGO)
Legal in Commander