Akkorokamui

A monster in Japan, but also seen in Taiwan and Korea. John Batchelor writes the following in his book The Ainu and Their Folklore:

... three men, it was said, were out trying to catch a sword-fish, when all at once a great sea-monster, with large staring eyes, appeared in front of them and proceeded to attack the boat. The monster was round in shape, and emitted a dark fluid which has a very powerful and noxious odour.

It's enormous body can reach up to 120 meters in length, the color is bright red and glowing. Just as the giant squids and octopus, the Akkorokamui can self-amputate and regenerate limbs.