If you've not met Cornelius, he's a middle-aged politician who ran afoul of the Lubii noxius
virus. It scrambled his genes with those of all previous hosts of the strain, leaving him fifteen feet of grouchy periwinkle amphibian thing. Because of magical cellular memory he can, for a few hours at a time, force his body back into his precious lost human form. He despises his new shape in every way and will lament his condition for hours if you get him started. But deep down he can't argue he's not a more empathetic person for the experience.
Anyhoo, wanted to practice actually moving him around as a monster. --
Cornelius' tail is the driving force when he swims, his limbs are pretty much just for steering/kicking off things/batting fish out of his way.
Because this body just happened and didn't evolve like a reasonable creature, he's not particularly suited to do anything in particular. Amphibious describes him well. He's both bipedal and quadrupedal but not super graceful either way. His eyes are suited for seeing underwater and suck on land while his lungs are awesome and work much better than his gills. He is a damn excellent swimmer, but he's never actually liked swimming all that much.
Don't think I've explained his gills. He does have them in addition to lungs but they're kind of crap and if he's doing anything strenuous he holds a breath of dry air as well. The systems aren't connected so he can swim with his mouth open to pass water through his gills in addition to holding his breath. He has burly lungs in the style of dolphins and can hold his breath comfortably for seven minutes. He can, and does, sleep underwater using just his gills and can do so indefinitely. After leaving water his gills stick flat to his neck and ooze a slime which congeals over them. After a half hour or so they're sealed shut, smooth and dry. Contact with liquid dissolves the protective layer immediately. He will not thank you for throwing water at him to try this out.
The other living glatni: