Well, Bagon has no wings and an incredibly hard head--they tend to have a habit of leaping off things in an attempt to fly. Its second stage is Shelgon, which looks rather like a shell with legs sticking out of it, and it's far more sedentary than previously. Salamence is its final form, and unlike before it does have wings, and quite enjoys making use of them.

For dragon types in general, there's quite a variety, actually. Many do resemble what most people seem to think of as "dragons," but not all. Goodra's early forms look more like blobs or slugs than dragons, while Flygon's first two stages resemble insects more than anything. As a type, it's resistant to many of the basic types--fire, water, and so on--and weak to ice and fairy as well as itself.