Speedbrood Stalker 
Creature — Insect Assassin
Flying, Lifelink When this creature enters, choose target opponent. Secretly choose a creature or planeswalker that player controls. That player sacrifices a creature or planeswalker of their choice, then sacrifices the chosen permanent.
Legality
standardNOT LEGALpioneerNOT LEGALmodernNOT LEGALlegacyNOT LEGALvintageNOT LEGALcommanderNOT LEGAL