On the iCarly episode when they try to break the world record, at the begging, Freddie says, "I hate to see a teacher cry like that." and Carly says its cause his last name is Buttwipe. But after Freddie takes Sam's book, Mr.Butt'wipe' is coming up the stairs with kids behind him saying "MR. BUTTBURN!". I thought it was Mr.ButtWIPE. Then Carly says "Aw, poor Mr.Buttburn."

(I'm not sure if this is accurate, i don't have a rewind button so i couldn't watch the part again, so...)