Assembly-Worker

Crawlspace

No more than two creatures can attack you each combat.

Servo

Chief of the Foundry

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

Altar of the Brood

Whenever another permanent you control enters, each opponent mills a card.

Golem

Torpor Orb

Creatures entering don't cause abilities to trigger.

Ankh of Mishra

Whenever a land enters, this artifact deals 2 damage to that land's controller.

Coat of Arms

Each creature gets +1/+1 for each other creature on the battlefield that shares at least one creature type with it. (For example, if two Goblin Warriors and a Goblin Shaman are on the battlefield, each gets +2/+2.)

Boarded Window

Creatures attacking you get -1/-0.
At the beginning of each end step, if you were dealt 4 or more damage this turn, exile this artifact.

Thopter

Omen Machine

Players can't draw cards.
At the beginning of each player's draw step, that player exiles the top card of their library. If it's a land card, the player puts it onto the battlefield. Otherwise, the player casts it without paying its mana cost if able.

Mindcrank

Whenever an opponent loses life, that player mills that many cards. (Damage causes loss of life.)