Sijaer

Created in ancient days by the four legendary Creator mages, the sijaer was a mistake. A cross between a giant squid and a shark, the sijaer has the head and dorsal fin of the shark, with the many tentacles of a squid. The sijaer is savage, untamable, untrainable, and uncontrollable. Ships have been attacked and split into pieces by a single sijaer. When the "Creators" discovered they couldn't control the sijaer, they tried to kill them -- but they had made the creatures nearly impervious to magic.