Idiot Plot: The second book. Jody is given amnesty for everything that's happened on the condition that she leaves San Francisco. Guess what she doesn't do. Then when shit starts going down... Guess what she still doesn't do.
Squick: The description of Jody's horribly burnt hand, the breast implants pushing themselves out, the necrophiliac coroner licking the melted gravy off a presumably dead Jody...
Take That: The plot and setup of the second and third books in the trilogy seems like this from Christopher Moore to his fans due to Fanon Dis Continuity and the rather bittersweet turn of the books.
Unwitting Instigator of Doom: The blue hooker in You Suck. She accidentally ingests some vampire blood after being drained by Tommy and becomes a vampire and makes a whole bunch of other vampires out of The Animals.