An extremely rare subspecies of Lagiacrus fought in the Underwater Ruin. Its shell is a lustrous black, and, unlike its cousins, it is bio-luminescent. As such, its body is covered in vivid blue points of light, a colour matched by its electricity-producing dorsal spikes and hood spines. Its eyes are a striking red that appear to glow amongst the murky depths, and the inside of its mouth is a vivid electric blue. The horns and spines on its head and upper neck are longer and more prominent than the other species of Lagiacrus.It appears to always be in a fully charged state, with all of its spikes constantly glowing at maximum power. It can fire electrical blasts from its mouth, very much like the Ivory Lagiacrus' blast, that send pulses of electricity everywhere. The Abyssal Lagiacrus is unique among its brethren in that it is known to use the motions of its serpentine body to create underwater whirlpools that can disorient hunters and set them up for a devastating blow.