A dunce or a fool. “A puffing, fuming, stupid creature.” (Brewer’s Dictionary of Phrase and Fable)

Bilbo Baggins, when trying to aggravate the Mirkwood spiders that had taken his dwarf companions captive, called them Tomnoddy, along with Attercop, Lazy Lob and Crazy Cob. The spiders became enraged at the insults and gave chase. Bilbo who was wearing his magic Ring of Power eluded them and was able to double back and free the dwarves.