Fatcoat

The fatcoat replaced its ancestor in its overlapping range. Its cotton pelt has mutated to cover its entire body again, supplemented by waterproofing oils to have it not cause drag exactly as it did in its ancestor's ancestor, and it is now straight instead of curly. This allows it to thermoregulate properly on land as well as water as a small creature. Speaking of, it no longer exists exclusively in water, as being a small plent with a heavy newborn size restriction and not being fully adapted for aquatic life, its ancestors' babies were extremely likely to drown immediately after birth and therefore they were under a massive selective pressure that led them to simply resume giving birth on land. This was extremely easy to do, as their legs were still well-developed and never actually lost any ability to be used on land. Its toe "bones" are broad and fused into flat, flexible paddles, which do not restrict its ability to walk while also making them function better for swimming. It has countershaded coloration, which makes it more cryptic.

The fatcoat has a powerful bite. It uses its prehensile tongue, which has a hand at the end, to snatch prey and pull it into its mouth. This is similar to the strategy employed by Terran cephalopods. It can administer an electric shock to stun smaller prey, but for larger prey it kills entirely using its bite. Its lower jaw no longer acts as a fin, as it did not provide much stabilization anyway and was better used as exactly what it is--a jaw. Its ears are small, but not nonexistent, and it senses vibrations in water better using fat that occupies the space where its dome once was. Speaking of, it lost its dome for the same reason it no longer uses its jaw as a fin--it was not assisting much in stabilization and, as a truly vestigial structure, it was completely lost. Its tail is short and points upwards so that the butt nostril may be quickly raised above water.

The fatcoat, as its name implies, is fat. When basking on shorelines, which it does regularly, it almost looks like a pathetic floppy sausage. Nonetheless, it is able to stand upright and waddle on land fairly well like a Terran penguin. Tropical populations are somewhat less fat, but still chubby, as being fat keeps them streamlined in water. It is social, basking, migrating, and hunting in groups of up to 30. As mentioned earlier, it gives birth on land, as it is not as aquatic-adapted as any secondarily aquatic animal that actually exists and can actually birth in the sea. Juveniles cannot dive at birth, as the limitations of plent reproduction and giving birth out their mouths forces them to be small, as it did in their ancestors--far too small to successfully fight currents and breathe. However, they are fluffy and able to float like ducklings or baby otters, guided and fed by their families swimming in the water below.

The fatcoat no longer has only one baby at a time (now 3-6) and gestates for considerably less time (1 month); in fact, its ancestor being listed as having 1 baby that gestated for a year was almost certainly an error, given its small size and mouth restriction that implied it somehow took a year to grow a baby that physically cannot be any larger than a rat. The fatcoat is very successful and can be found on every landmass. Its success can be owed in part to seafaring shrews, as it basks on their nests and on islands of driftwood that only exist as a result of their activity. This has allowed it to be able to technically bask and breed on open water through use of these floating structures.