Mm'menon, the Right Hand 
Legendary Creature — Jellyfish Advisor
Flying
You may look at the top card of your library any time.
You may cast artifact spells from the top of your library.
Artifacts you control have "
: Add . Spend this mana only to cast a spell from anywhere other than your hand."
Legality
standardLEGALpioneerLEGALmodernLEGALlegacyLEGALvintageLEGALcommanderLEGAL