Nimana Skitter-Sneak 
Creature — Human Rogue
As long as an opponent has eight or more cards in their graveyard, this creature gets +1/+0 and has menace. (It can't be blocked except by two or more creatures.)
Legality
standardNOT LEGALpioneerLEGALmodernLEGALlegacyLEGALvintageLEGALcommanderLEGAL