mbari.org

XEjJP TIL There is a deep-sea fish with a completely transparent head named Barreleye aka Spook Fish
4ddX TIL there is Vampire Squid that lives 600-900 Meters below water and is the only cephalopod in the animal kingdom to consume non living tissues, and has more teeth-like projections as opposed to suckers than a normal squid or octopus. Video in link.