Magnapinna squids are one of the deep-sea more ethereal creatures. Little is known of these squid as very few have ever been captured, although over the last decade with the increased usage of remotely operated vehicles (ROV) and submersibles more and more video is emerging of them. They are unusual in both that the fins are up to 90% of the length of the body, i.e. the mantle, and the ridiculously long length of the arms. The squid often will hold some of the arms at a 90˚ angles from the side of the body. Wikipedia has a nice entry on the history of their discovery.
On November 11, 2007., a Shell oil company ROV capture a Magnapinna on video (below) at a depth of 2386 meters (~1.5 miles). Someone (I’ve been unable to track down who created this), used the video to produce a single image of this individual (above). It was subsequently posted to Reddit. Love the image of this fascinating creature.
Also nice a User Art from Deviantart: