Get ingredients, have skill, build wind-up deathbot. Lasts a certain number of turns before it runs out of juice and selfdestructs/shuts down.
Multiple ways this can be done. Basically have Tinkering skills to build the multiple components necessary to construct the robopet, and either the skill to activate it (by sacrificing the object and summoning a construct monster), or basically toss it like a projectile, which causes the monster to spawn at the location where you tossed it, as well as cause damage to the monster you tossed your own monster at.
This is very easy to do. I don't see the point in making it self destruct since it can't leave the floor it was built on.
Reminds me of the robotic automaton you can "summon" in Arcanum if you can find the recipe, and have the parts for it, they also had awesome robo spiders, like a healing robo spider or a standard attack one. And at the end, you can also click back on it to turn it back into it's component and stuff it back into your inventory. They were insanely strong, capable of damaging your armor when attack you, and your melee weapons suffered durability penalties when attacking them. They were balanced by the fact that they moved really slowly (the mechanical arachnids, I don't quite remember the automaton as much). But yeah, it would be fun to see them in a game again.
