The Red Mist is a Octopus. Only appeared in the Darius Twin game.
Red Mist makes it a point of honour to squash you against the screen. He is a pretty big fellow and is up to the job, for sure. His weak spot is, not surprisingly, his head, but it can only be reached when the hatch guarding it opens, and that is coupled with an attack. But we're getting ahead of things here. He starts off with a tentacle wave, and then opens his head to fire three fat, rotating, rugby ball-shaped bullets. After this comes more tentacle-waving. After this he floats upwards and very ungraciously unloads several mines on you. They will explode into four more mines if shot, so watch out.