Although no official source has yet to give the etymology behind Deutalios' name, his Japanese name is similar to the chemical Deuterium, a rare form of Hydrogen which features two protons instead of the usual one found in normal Hydrogen. This is fitting, as Deutalios is comprised of parts from two separate organisms to create a hybrid chimera.
Deutalios resembles a cross between a rat and various fish. He has a long, whip like tail and extended ears which appear to display gills on them. For a creature that was adapted to living in water, Deutalios appears to have retained its long fur.
Godzilla was going to fight Deutalios instead of the Super X2 and the Rose form of Biollante. Godzilla would have fought, killed, and consumed Deutalios, confirmation that Godzilla is carnivorous. The monster was possibly dropped due to the graphic nature of this scene.