I don't think the "Not here to make friends" one really works for me, since in my play I generally do make friends. That said, there's a few other players I could recommend that title for.
The "Et tu?" and "Ides of Mash" one are both rather amusing, and the latter seems to have a lot of support.
Anyway, other possibilities I've thought of.
"Knife target" (self explanatory)
"Jury member" (Haven't missed merge yet, but still haven't made FTC.)