Ravener 
Creature — Tyranid
Flash Ravenous (This creature enters with X +1/+1 counters on it. If X is 5 or more, draw a card when it enters.) When this creature enters, target creature attacks target opponent this turn if able.
Legality
standardNOT LEGALpioneerNOT LEGALmodernNOT LEGALlegacyLEGALvintageLEGALcommanderLEGAL