Another reliable form of humor, which might be called irony's cousin, is incongruity, the pairing of two
generally accepted incompatibles; one of my favorite examples of this
comes (again) from the Freddy books: it's found
in the character of Leo the Lion, who has a penchant for getting permanent
waves to keep his mane looking spiffy («And I ought to have another permanent; there isn't hardly a crinkle left
in the darn thing»).