The word ban·der·snatch (noun \ 'ban-dər-snach' \) was coined by writer Lewis Carroll. It appears in the second verse of his famous nonsense poem, Jabberwocky, which is found in the first chapter of Alice Through the Looking Glass (1871). This, of course, is the same Alice who adventured through Wonderland in an earlier book.
It’s a poem stuffed with barely comprehensible gibberish that somehow, still seems loaded with meaning. And if you can find a Random House or Merriam-Webster's Unabridged Dictionary, they offer up two definitions:
Perhaps more to the point: a bandersnatch is a fictional character within a piece of fiction that is inside another piece of fiction, and written backwards so that it needs to be read in front of a mirror. The only way to describe a bandersnatch is by what is inferred from one of Carroll’s invented adjectives in front of it: frumious. Create a visual in your mind.
“It seems to fill my head with ideas,” says a beguiled Alice, “only I don’t know exactly what they are...”