Arcbound Mouser

Lifelink
Modular 1 (This creature enters the battlefield with a +1/+1 counter on it. When it dies, you may put its +1/+1 counters on target artifact creature.)

Arcbound Hybrid

Haste
Modular 2 (This creature enters the battlefield with two +1/+1 counters on it. When it dies, you may put its +1/+1 counters on target artifact creature.)

Fling

As an additional cost to cast this spell, sacrifice a creature.
Fling deals damage equal to the sacrificed creature's power to any target.

Arcbound Prototype

Modular 2 (This creature enters the battlefield with two +1/+1 counters on it. When it dies, you may put its +1/+1 counters on target artifact creature.)

Atog

Sacrifice an artifact: Atog gets +2/+2 until end of turn.

Arcbound Tracker

Menace
Modular 2 (This creature enters the battlefield with two +1/+1 counters on it. When it dies, you may put its +1/+1 counters on target artifact creature.)
Whenever you cast a spell other than your first spell each turn, put a +1/+1 counter on Arcbound Tracker.

Great Furnace

Ancient Den

Arcbound Worker

Modular 1 (This creature enters the battlefield with a +1/+1 counter on it. When it dies, you may put its +1/+1 counters on target artifact creature.)

Arcbound Stinger

Flying
Modular 1 (This creature enters the battlefield with a +1/+1 counter on it. When it dies, you may put its +1/+1 counters on target artifact creature.)

Arcbound Bruiser

Modular 3 (This creature enters the battlefield with three +1/+1 counters on it. When it dies, you may put its +1/+1 counters on target artifact creature.)

Rusted Slasher

Sacrifice an artifact: Regenerate Rusted Slasher.

Arcbound Slasher

Modular 4 (This creature enters the battlefield with four +1/+1 counters on it. When it dies, you may put its +1/+1 counters on target artifact creature.)
Riot (This creature enters the battlefield with your choice of an additional +1/+1 counter or haste.)