New monster idea

[Yqatuba]

How about a colossus that can build golems inside itself? (Think like Master Mold from X-men). I'm not sure how it would work though.

[Darigaaz the Igniter]

Give it an internal capacity (kinda like a non-hazardous swallow whole) for how many of the golems it can hold at a time. Set a time for how long it takes to make a golem. Let it "spawn" a golem as a full-round action by placing the golem adjacent to itself. Have it go around "eating" raw materials of the type needed to create the intended golems. Depending on how you're envisioning it, the walking factory can either be resilient but not particularly dangerous on its own, or it can be a challenging colossus in its own right with the golems being minions.

[Kayerloth]

Or a Golem which is actually a swarm of "nano-golems". Like Darigaaz suggests above maybe it breaks off small swarms every now and then. Perhaps when around sufficient raw materials to form another golem it buds off another swarm, both smaller than the original which then proceed to engulf and assimilate the raw materials available and grow.