Steve, World-Builder

Artifacts you control are Equipments with "Equipped creature gets +x/+x where x is the converted mana cost of the artifact." and "Equip {1}" and still keep their abilities.
When Steve enters the battlefield or attacks, choose one.
-Create a 1/1 green zombie token.
-Create a colorless block artifact token with "{t}: add {1} to your mana pool."