Golem Foundry

Whenever you cast an artifact spell, you may put a charge counter on Golem Foundry.
Remove three charge counters from Golem Foundry: Create a 3/3 colorless Golem artifact creature token.

Losheel, Clockwork Scholar

Prevent all combat damage that would be dealt to attacking artifact creatures you control.
Whenever one or more artifact creatures you control enter, draw a card. This ability triggers only once each turn.

Steel Overseer

{T}: Put a +1/+1 counter on each artifact creature you control.

Plains

Chief of the Foundry

Other artifact creatures you control get +1/+1.

Gold Myr

Tempered Steel

Artifact creatures you control get +2/+2.

Starnheim Courser

Flying
Artifact and enchantment spells you cast cost {1} less to cast.

Foundry Inspector

Artifact spells you cast cost {1} less to cast.

Dispatch

Tap target creature.
Metalcraft — If you control three or more artifacts, exile that creature.

Stonecoil Serpent

Reach, trample, protection from multicolored
Stonecoil Serpent enters with X +1/+1 counters on it.