Lashknife 
Enchantment — Aura
If you control a Plains, you may tap an untapped creature you control rather than pay this spell's mana cost. Enchant creature Enchanted creature has first strike.
Legality
standardNOT LEGALpioneerNOT LEGALmodernNOT LEGALlegacyLEGALvintageLEGALcommanderLEGAL