I've heard that if a shark attacks you, you should hit it on the nose and gills.
There are victims who said such actions appeared to drive the shark away, but researchers tested such actions and determined that the sharks just decided to cease attacking, since being hit on the nose and gills with human strength didn't appear to bother them in the least. Still, its best to try SOMETHING rather than just let it eat you.
Go for the eyes Boo! Go for the eyes!
Oo, Death Rolls! We had those at dinner last night!And if you're looking for game rules for a grab-n-shake type attack, check out the crocodile's death roll attack.

(Dungeons & Dragons)
Rulebook featuring "high magic" options, including a host of new spells.