Very funny stuff in this thread. I love the maintenance guys!
Here's my stuff:
The dwarves, in their pride and greed, delve too deeply and...
...awaken a cranky Balrog who sues them for trespass and violation of his mineral rights.
...encounter greedy, prideful dwarves from the other side of the world who have also delved too deeply, thus creating a handy shortcut through the center of the planet.
...flood their basement.
...have to shut down their mines by government edict due to toxic mold, Radon, Carbon Monoxide, etc.
The Evil Wizard amasses his vast armies of Orcs and Goblins for an all-out assault on the besieged Kingdom-of-the-Good-Guys, but is confronted by representatives of the Brotherhood of Orcish Combat Workers (BOCW, Local 242) demanding more pay, better equipment ("Half our guys are carrying clubs, for goodness sake!"), and a health plan. Goblin labor leaders threaten to walk off the job if the E.W. doesn't do something to fix the hostile work-environment the Orcs are creating for them.
Mind Flayers speak with a lisp and are self-conscious about their slimy, soft heads.
Beholders go in for elaborate corrective lenses and occasionally have to stop in mid-battle because one of their contacts lenses has come out.
I don't know if those are really cliches, but I made myself laugh thinking them up, so I hope you like 'em...