This technique, developed by Amachi due to Orochimaru's initial interest of creating the ultimate underwater ninja, drastically changes the user's appearance, giving them green scale-like skin, fins, and gills.
The Kaima (海魔, Literally meaning: Ocean Demon) transformation can also change the user's eye colour, as seen in Amachi's case. This form gives them supreme fighting skills in the water, as they can move through the water much faster than normal, as well as giving them the ability to breathe underwater. Also the scales used in this form have a steel like quality that can stop a kunai. Amachi also demonstrates that he can shoot the scales as a weapon.