The Mangrove Saltmarsh Snake (Nerodia clarkii compressicauda) appears to use its tongue to lure its fish prey. The ‘luring tongue flicks’ were longer in duration than the normal ones, involved curling, and were only observed when the snakes were foraging for prey. This behavior has also been documented in Aquatic Garter Snakes (Thamnophis atratus) although they did not engage in the strange curling.
Hansknecht, K. (2008) Lingual Luring by Mangrove Saltmarsh Snakes (Nerodia clarkii compressicauda). Journal of Herpetology 42(1) 9–15