Great, now I'm afraid of octopi

Damn straight.

I have seen one flat, instantly, kick the sh.t out of a diver that was
trying to pull him out of a den (dont ask me, I was screaming "NO! NO! into
my reg),
and big (as in 4 to 4.5 foot) ling cod.

These things get 16 to 20 feet long (600 pounds is the record), and are King
of the Beach in their realm.

They absolutely do not fear anything underwater, and divers are either
nuisance or a curiosity to them.

I have had some great interactions with them, but always slowly and with the
utmost respect.

http://www.npca.org/marine_and_coastal/marine_wildlife/octopus.asp