I've always loved this kind of stuff. Pity most of the cool ones are already posted. Still, enjoy the immature dragonfish, gulper eel, tripod fish, bone-eating snotflower, giant isopod and stemmed crinoid respectively.
[hider=Images][img=http://bogleech.com/nature/abyss-dragonlarva.jpg]
[img=http://awesomebluestuff.files.wordpress.com/2011/07/gulper-eel.jpg]
[img=http://2.bp.blogspot.com/_jhW52aMy8UU/TQ7ayevoWyI/AAAAAAAACCU/KD5PZ38GsNo/s1600/Tripod-fish-2.jpg]
[img=http://www.nhm.ac.uk/resources-rx/images/1008/snotflower-490_67393_1.jpg]
[img=http://c85c7a.medialib.glogster.com/media/34/34c946c982a7a019a09d9c1e5ba3afea69742f3be3ff1290b68013763b74b4ec/giant-isopod-5-slideshow-604x500-jpg.jpg]
[img=http://scienceblogs.com/zooillogix/wp-content/blogs.dir/253/files/2012/04/i-22c9727458f86a38f776395039ce4827-crinoid%20creeping.gif]
[/hider]

Ed: Did we somehow forget hagfish?
[hider=Squirm][img=http://naturefilmsnetwork.com/blog/wp-content/uploads/2011/10/New-Zealand-hagfish-teeth.jpg]
[img=http://people.whitman.edu/~yancey/hagfish.jpg]
[img=http://www.wired.com/images_blogs/wiredscience/2011/03/hagfish-linda-snook-noaa-cbnms.jpg]
[img=http://nature.ca/explore/di-ef/images/05_hagfish_whale_s_cr.jpg][/hider]