What's Her Face was being sarcastic when she suggested killing someone off in the Tenthennial Issueversary.
- What's Her Face is usually the only character with any common sense in the series, so she likely would've realized a big problem with killing off one of the characters. Strong Bad, being Strong Bad, wouldn't care if she was being sarcastic about it, and so he killed all four girls more spontaneously than usual.
The Maniac in a Speedo in Issue 11...
- ...is the Arrow'd Guy.
The Arrow'd Guy is a shapeshifter. Or possibly a Physical God.
- According to the wiki, he may also be Judith So-And-So-erson and is the baby who kills Tompkins by being babysat. Also, at the end of "Teeny Tiny Girl Squad", he appears as a giant. This shows that he can change form, except for his baldness. He's also able to appear from the sky much the same way as God did in Monty Python and the Holy Grail to taunt and kill What's Her Face. This could also tie into the Maniac in a Speedo theory above as well.