Well since I did wyverns, it was only fair I tried gryphons as well
Gryphons were even harder than wyverns to get decent skins for, but WAY more fun. The gryphon model seems far more detailed, less blocky than the wyvern one. But also because they're half birds (and bird plumage can range anywhere from drab to shiny and bright) you can get away with some really interesting colours.
One problem I ran into early on was the beak. For some reason the beak texture on the black gryphon looks as if someone sloshed a broad paintbrush across it a few times (the other two colours are not like this). It's not so obvious with the in-game skin, but when you apply other colours and shades it starts to look terrible. And because I'd used parts of the black skin in most of mine, the effect started to contaminate everything. As a result, many of the gryphons ended up with beaks that were copied, recoloured and pasted from decent beaks. I also used a lot more adjusting of the hue/saturation/lightness than I ever had in the past. It was just too hard to get passable colours any other way. It was a fun learning experience.
Anyway, on with the skins!
Firstly a few basic colours with light bodies; blue, tan, rose and purple. The first blue is my original, but I started to like the indigo/silver combo on the second and decided I couldn't leave it out:




A rich gold and brown. Texture like... well, marigolds I guess:
A couple of stately sombre colours. Burgundy, and olive green:

High on the icy slopes of Ironforge, a rare frost gryphon:
Some strong but dark plumage, with dark bodies...
Crimson (inspired by a parrot):

Old Gold (never planned this one, it just kind of happened):

Cobalt (also parrot-inspired):
Another tropical parrot-inspired one. Emerald with orange highlights. I can imagine it down in a steamy jungle:
Lastly, two very bright ones. Perhaps too bright. The originals almost left permanent scars on my retinas. Rather than discard them I decided to tone them down a bit and post them anyway

Again, I can imagine these in a tropical environment (or up in Eversong Woods!).
Green/Yellow and Purple/Pink:

Again, thanks to Spiritbinder and Kurasu for their advice and for putting up with all my spam mails
