Now I realized what I forgot to write in his trivia section. Veles can transform into a gigantic hybrid of snake/dragon (according to Slavic myth, they tend to bundle dragons together with giant snakes as Zmey). He hasn't transformed for centuries and certainly not wanting to do it right now in the 21st century because he knows he'll either end up in a zoo or lab as experiment subject. Worse yet humans probably 'punch him in the face' with nuclear warhaed missiles.
Another OC who can shift into animal form is Ludovica but it's difficult to say what is his animal form exactly since it's a hybrid mess of several species.