Manuel on Buffoonery posts this interesting series of pointers to tako pr0n.
Whybark got me going on Japanese octopus porn with this tip: famous ukiyo-e painter Hokusai's awabi fisher and octopus (c.1814). Fast-forward to 2001, when Masami Teraoka painted Sarah and Octopus/Seventh Heaven. Toshio Saeki's Octo-girl takes the classic tentacle porn for a spin.
What's up with the Japanese obsession with octopus sex?
I'm still looking into it.Check the comments for the definitive guide. I did find this one strange story on Dr. Kilmarnock's Obscure World of Victorian Erotica: Tentacles of Desire: The Man who Loved Cephalapods. Look at that old pervert! It's me in 40 years!
For scientific posterity, here's some information on actual octopus sex, including a line drawing of hot hectocotylus/mantle cavity action. And here's the original octopus porn link that started it all.
Most of the links are not worksafe, duh. Regarding that last link (to hardcore images), ultra-observant BoingBoing reader Brian says, "Wow. They have a condom on the thing… and it's tentacles are tied up above her legs so as to give the illusion of life and intent. The thing is dead. That's not just octoporn… thats necroctoporn!" Link (Thanks, Susannah!)