Niblis of Frost 
Creature — Spirit
Flying Prowess (Whenever you cast a noncreature spell, this creature gets +1/+1 until end of turn.) Whenever you cast an instant or sorcery spell, tap target creature an opponent controls. That creature doesn't untap during its controller's next untap step.
Legality
standardNOT LEGALpioneerLEGALmodernLEGALlegacyLEGALvintageLEGALcommanderLEGAL