Tentacle erotica

Tentacle rape or shokushu goukan (触手強姦) is a concept found in some horror hentai titles, where various tentacled creatures (usually fictional monsters) rape or otherwise penetrate women, anthropomorphous creatures, Futanari and, less commonly, men. The genre is quite popular in Japanese erotica, and is even the subject of much parody. For Western audiences, tentacle erotica often symbolizes hentai as a phenomenon.

History
Tentacled creatures appeared in Japanese erotica long before animated pornography. Among the most famous of the early instances—and perhaps the first—is an illustration from the novel Kinoe no komatsu of 1814 by Katsushika Hokusai. It is an example of shunga (Japanese erotic art) and has been reworked by a number of artists. Australian artist David Laity reworked the design into a painting of the same name, and Masami Teraoka brought the image up to date with his 2001 work "Sarah and Octopus/Seventh Heaven", part of his Waves and Plagues collection.

A scholarly paper by Danielle Talerico showed that although western audiences have often interpreted Hokusai’s famous design as rape, Japanese audiences of the Edo period would have associated it with consensual sex. Edo audiences would recognize the print as depicting the legend of the female abalone diver Tamatori. In the story, Tamatori steals a jewel from the Dragon King. However, during her egress, the Dragon King and his sea-life minions (including octopodes) pursue her. Furthermore, within the dialogue in the illustration itself, the diver and two octopodes express mutual enjoyment.

Culture
In 1990, Toshio Maeda's manga Demon Beast Invasion created what might be called the modern paradigm of tentacle porn, in which the elements of sexual assault are emphasized. Maeda explained that he invented the practice to get around strict Japanese censorship regulations, which prohibit the depiction of the penis but apparently do not prohibit showing sexual penetration by a tentacle or similar (often robotic) appendage.

The use of sexualized tentacles has also appeared in American and European films, although with far less frequency. While the historical context of tentacle erotica as a Japanese phenomenon cannot be denied, the use of it in modern films, both B-movie and adult-oriented erotica, may have been given a boost due to Roger Corman's Galaxy of Terror, released in 1980. In that film, a female astronaut, played by Taaffe O'Connell, is captured, raped and killed by a giant worm. The worm uses its many tentacles to first strip the astronaut naked, then penetrate her.