jabberwocky

In a poem titled "Jabberwocky" in the book Through the Looking-Glass and What Alice Found There (1872), Lewis Carroll warned his readers about a frightful beast:

Beware the Jabberwock, my son!
The jaws that bite, the claws that catch!
Beware the Jubjub bird, and shun
The frumious Bandersnatch!

This nonsensical poem caught the public's fancy, and by 1908 jabberwocky was being used as a generic term for meaningless speech or writing. The word bandersnatch has also seen some use as a general noun, with the meaning "a wildly grotesque or bizarre individual." It's a much rarer word than jabberwocky, though, and is entered only in the Merriam-Webster Unabridged Dictionary.