Sidisi, Brood Tyrant 
Legendary Creature — Snake Shaman
Whenever Sidisi enters or attacks, mill three cards. Whenever one or more creature cards are put into your graveyard from your library, create a 2/2 black Zombie creature token.
Legality
standardNOT LEGALpioneerLEGALmodernLEGALlegacyLEGALvintageLEGALcommanderLEGAL