Creature — Crocodile 5/5, 3G (4)
Rare
When you control no other creatures, sacrifice Emperor Crocodile.
The king of Yavimaya's waters pays constant attention to his subjects . . . and thrives on their adulation.
Illus. Kev Walker

10/4/2004: The ability will trigger if you don't control another creature, even for a brief moment during the resolution of another spell or ability.
10/4/2004: Only checks if you control no other creatures at the time it triggers. It does not check again on resolution, so gaining control of a creature before then will not save the Crocodile.
Legal in Vintage (Type 1)
Legal in Legacy (Type 1.5)
Legal in Classic (MTGO)
Legal in Commander
Legal in Modern