Manaplasm 
Creature — Ooze
Whenever you cast a spell, this creature gets +X/+X until end of turn, where X is that spell's mana value.
Legality
standardNOT LEGALpioneerNOT LEGALmodernLEGALlegacyLEGALvintageLEGALcommanderLEGAL
Creature — Ooze
Whenever you cast a spell, this creature gets +X/+X until end of turn, where X is that spell's mana value.