Strong Bad has used "bulltonk" and "bullhonkey", the latter later being turned into the name of an energy drink (a parody of Red Bull).
"What the pfargtl?!" is used once and referenced within the same episode as the acronym "WTPF."
Homestar Runner himself refers to his butt as his "tweese", even though he's actually said "butt" before (apparently it's a shortened form of "buttweesimo"). He has also said, "Sweet genius, that hurt!"
Marzipan then later calls Strong Bad a horse's tweese.
Strong Sad has peculiar elephant feet. He calls them "soolnds".
In the DVD commentary for the sbemail "technology", Matt says "parg" when Mike tells him to swear.
In one halloween special, after Bubs and Coach Z come to the door, their response to the candy they get:
Bubs: Aww, zagnut!
Pimp Lando has its title character's catchphrase, "What the foo?!?"