An epic fight between an octopus and an eel led the snorkeler at risk, as the frightened and defeated eel started swimming directly at him with its jaw open.

If you watch it closely, you can see that the eel managed to tear off one of the octopus’s arm. 

source: http://www.dailymail.co.uk/news/article-3826853/Moray-eel-attacks-snorkelers-battling-octopus.html