The first illustration is the "Winged Serpent" Wyvern or Gwiber type, shown as if it were an Ouroboros. In this case I thoought it was an important depiction because it is obviously feathered and has a feathered neck, but also thatit is feathered in green and that the long green feathers of its tail have ocelli like a peacock's tail. The reminisces of Gwibers in Wales mentioned that their bodies were feathered and gaudy. and the feathers resembled peacock feathers. I wrote a blog for the CFZ in which I identified these "Flying serpents" as a sort of long-tailed pheasant-like bird and this looks like the illustration is going right along with the identification. It also seems to have a couple of feather tufts or "Horns" on its head, as some other more usual pheasants do.
The first part of this article was reprinted in Richard Muirhead's journal FLYING SERPENTS (April 2011) and the part two is now pending. It had been a recent blog entry at that time and one of the first articles on the current blog was a posting on New World Flying Serpents (Amphitheres)which was a follow-up from the CFZ articl;e on Gwibers.
This illustration was labelled as a dragon slaying as illustrated in Lucas Jennis' Bestiary. This would once again be one of the "Flying serpent" Wyverns or Cockatrices. It is interesting in that it seems to be another long-tailed bird but that the long trailing tail is interpreted as a snake's tail. In the case of a pheasant the long tail feathers are not exactly stiff bur can bend and curve around to some extent. I had some photos illustrating this in my CFZ blog on Gwibers (and in the reprinted article)
This is another bestiary illustration indicated as coming from the renaissance period but in Northern Europe, possibly Germany (or Holy Roman Empire as it was then) In this case (one of a few others I have found like it), it seems the "Dragon" or Dragonet is a Master-otter: a nursing mother if the artist isn't being extravagent. The creature would appear to have a full set of teats. The style is probably from the 1500s and this kind of "Dragon" depicted from the British Isles up through Scandinavia. There is some confusion of types because "Salamanders" would be illustrated as just about the same: the size of this one would probably be more the size of a "Salamander".
Best Wishes, Dale D.