Skilled Animator

When Skilled Animator enters, target artifact you control becomes an artifact creature with base power and toughness 5/5 for as long as Skilled Animator remains on the battlefield.

Island

Broodstar

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
Flying
Broodstar's power and toughness are each equal to the number of artifacts you control.

Stoic Rebuttal

Metalcraft — This spell costs {1} less to cast if you control three or more artifacts.
Counter target spell.

Tezzeret, Cruel Machinist

+1: Draw a card.
0: Until your next turn, target artifact you control becomes a 5/5 creature in addition to its other types.
−7: Put any number of cards from your hand onto the battlefield face down. They're 5/5 artifact creatures.

Silver Myr

Master of Etherium

Master of Etherium's power and toughness are each equal to the number of artifacts you control.
Other artifact creatures you control get +1/+1.

Thoughtcast

Affinity for artifacts (This spell costs {1} less to cast for each artifact you control.)
Draw two cards.

Darksteel Citadel

Ensoul Artifact

Enchant artifact
Enchanted artifact is a creature with base power and toughness 5/5 in addition to its other types.

Ornithopter

Tezzeret the Seeker

+1: Untap up to two target artifacts.
−X: Search your library for an artifact card with mana value X or less, put it onto the battlefield, then shuffle.
−5: Artifacts you control become artifact creatures with base power and toughness 5/5 until end of turn.

Seat of the Synod

Spire Golem

Affinity for Islands (This spell costs {1} less to cast for each Island you control.)
Flying

Phyrexian Metamorph

({U/P} can be paid with either {U} or 2 life.)
You may have Phyrexian Metamorph enter as a copy of any artifact or creature on the battlefield, except it's an artifact in addition to its other types.