...any more ideas we can appropriate from Dungeons of Dredmor while we're at it? 
Switches that open up hidden rooms? Traps that shoot from a wall when you step on a specific tile? BraxBots which you can buy one random item from, but spawn multiple DreadBots if you kill it? Diggle hell?
Well there are
Robot Zoos.
And a
DiggleBot as a tribute would not hurt as well, I guess
. Maybe some bot that only has a closed quarters attack and moves to more or less random squares by "digging" through the ground? It could also have different colored variants that transfer a debuff on the player on contact/stop digging and rage attack against the player in a straight line once they have been hit .
Although this could be a little too much !!fun!!
.
Maybe having it use it's special movement only every other move or similar would be a workable compromise.
As far as an exploitable weakness goes they could either be allowed to dig out at tiles occupied by other bots, potentially self-destructing (and dealing damage) in the process OR
there could be a designed diggle nest tile that, if attacked enrages the DIggleBots and lets them attack everything (similar to the RazorBot).
Mantised
here.
