Argothian Opportunist 

Creature — Human Scout
When this creature enters, create a tapped Powerstone token. (It's an artifact with ": Add
. This mana can't be spent to cast a nonartifact spell.")
Legality
standardNOT LEGALpioneerLEGALmodernLEGALlegacyLEGALvintageLEGALcommanderLEGAL