Siren of the Fanged Coast 
Creature — Siren
Flying Tribute 3 (As this creature enters, an opponent of your choice may put three +1/+1 counters on it.) When this creature enters, if tribute wasn't paid, gain control of target creature.
Legality
standardNOT LEGALpioneerLEGALmodernLEGALlegacyLEGALvintageLEGALcommanderLEGAL