Momon is a Virus Attribute Digimon designed for unknown reasons. Some say it was to replace Jamon, but others are unsure as to what it's fully capable of. It looks like a fish, but it is actually a reptile, giving even more confusion as to what it's capable of. It's jaws are designed for more soft bodied prey, and even as this form it's already very aggressive. Whether Momon is the replacement of Jamon is uncertain due to it requiring air to breath where Jamon can breath underwater, unlike Momon. Some say it's creation was brought about due to leftover energy needed to be used in-order for the universe to still exist. Compared to Fiamon, which is based on a Prehistoric Mammal like Chowmon's line, and Obamon, which parodies real life evolution like Minmon's line, Momon's line is based off a Prehistoric Aquatic animal that becomes a cyborg in the final form.
Digimon World: Aftermath