Restless Bones 
Creature — Skeleton
, 
: Target creature gains swampwalk until end of turn. (It can't be blocked as long as defending player controls a Swamp.)
: Regenerate this creature.
Legality
standardNOT LEGALpioneerNOT LEGALmodernLEGALlegacyLEGALvintageLEGALcommanderLEGAL