Qasali Ambusher 
Creature — Cat Warrior
Reach If a creature is attacking you and you control a Forest and a Plains, you may cast this creature without paying its mana cost and as though it had flash.
Legality
standardNOT LEGALpioneerNOT LEGALmodernLEGALlegacyLEGALvintageLEGALcommanderLEGAL