Bloodhall Ooze
Conflux — rare
Creature — Ooze
Bloodhall Ooze rulings:
2009-02-01: The “intervening ‘if’ clause” means that (1) the ability won’t trigger at all unless you control a permanent of the specified color, and (2) the ability will do nothing unless you control a permanent of the specified color at the time it resolves.
2009-02-01: A permanent that’s both black and green will allow both abilities to trigger (as will separate black permanents and green permanents, of course).