Mishra, Excavation Prodigy 

Legendary Creature — Human Artificer
Haste
,
, Discard a card: Draw a card.
Whenever you discard one or more artifact cards, add
. This ability triggers only once each turn.
Legality
standardNOT LEGALpioneerLEGALmodernLEGALlegacyLEGALvintageLEGALcommanderLEGAL