What Kind of Creature Am I?

Started once upon the thyme, where a lot of brave and awesome stories start Under some old oak and pines, in the time between the summer and the winter Rolling in an open grave, we see an egg about the size..uh..of an egg? By a monotreme was it laid? Or maybe by a GIANT MADE OF ROCK? ;) oh! Never mind it's origin! We hear and see the egg (of course) begin to crack And slithers out, a creature grey, wearing tiny face full of wonder From a slither to a crawl, the creatures of the bush all introduce themselves Little things like "I'm a bird!" or "I'm a fish!" or "I'm a hungry snake!!" (Scream) He met a lot of things that day, and surely went and met a few ones more Walking now, he found a lake, and he was heard to say; "See. Me? Is that I in Lake reflection? Sloth-hairy, bat-of-a-wing, but Thorny & horned like a rhino? Scale-tailed not unlike a dragon, oh! What kind of creature am I?? Heading further in the bush, it came across a weather-beaten sign - "Annual meeting of the owls - the smartest creatures in the region!" It was something of a barbeque...they were feasting there, on whiskey and sardines, When a crackle under clumsy paw caused them all to stop and turn around.... "We’ve never seen a thing like you! And we’ve seen every creature known to owl!" Gazing through their monocles, with their heads all a-swivelly (as owls do) Then, an information overdose, consulting every book that they could find - Everything from “Count the Frogs!”, to “Pigs and Hogs", to "Spot the Cephalopod!" The parliament was at a loss, hooting puzzled, till one came forth and said “Oh! We haven’t got a clue! But we know who will…” Jewel-eyed? underbite fangers...and whiskers? Claws, paws and toehidden™ blisters Surinam-toad-backed, with ink sac! Funnyboneless, and what's that? A blow hole there on the back of its neck?!? It travelled west (but too far inland...), following the leaf & charcoal map exactly as the owls had drawn. “It’s there” they said, “the weird all-knowing dwells. With mushroom suckers, and enormous brain (proportioned to its brawn.) Diving in the waters for the first time was at first alarming, (calming though it was, eventually) Following the pulsing rhythm of the triple-hearted one, our poor protagonist was heard to speak Failed to feel the water slowly boil, absorbing into bone Gigantism setting in and turning muscle into stone What kind of creature AM..... I?