Sir Isaac Newton (Between Planets, by Robert A. Heinlein)Read about the other entries on the list.
Few things are more satisfying than going on a Heinlein novel binge read, and Between Planets is a great book to start with. Aimed at young adults, the novel follows an Earthling teenager as he goes on an interplanetary adventure with Sir Isaac Newton, a space dragon from Venus. Just read it: it’s nutballs.
Also see John Mullan's list of ten of the best dragons in literature.
--Marshal Zeringue