"Slithy tove" is from the nonsense poem 'Jabberwocky' by Lewis Carroll, in Through the Looking Glass. The 'snark', if I remember correctly, is, along with the 'fumious bandersnatch' dispatched in short order by the nameless hero. (Or does the 'snark' show up only in 'The Hunting of the Snark'? Hmmm ... )