The Collapsible Frink, a simple and charming creature, apears in Seuss's Sleep Book. I forget the lines, but it's the creature with the extremely long neck which concertinas down when sleep is at hand.
/frink/ v. The unknown ur-verb, fill in your own meaning. Found esp. on the Usenet newsgroup alt.fan.lemurs, where it is said that the lemurs know what `frink' means, but they aren't telling. Compare gorets.