Unseen Walker 
Creature — Dryad
Forestwalk (This creature can't be blocked as long as defending player controls a Forest.)
: Target creature gains forestwalk until end of turn.
Legality
standardNOT LEGALpioneerNOT LEGALmodernNOT LEGALlegacyLEGALvintageLEGALcommanderLEGAL