You've FLOORED me.
Whatever you did to make them seem so much higher than the castle--it WORKS. RIDICULOUSLY WELL. And every character has an interesting expression--my fave is the racoon. Fantastic piece: teach me how to paint rocks. ;)
There are some nits I have...The people on the castle should be smaller, I think. Right now, it looks like the crenellations only come up to their knees, and in midieval times, those usually came up more to their chests. Right now, the li'l folks dont' look like they could fit inside their castle.
Second, I think the shading would be a little more vibrant if you'd used complementary color for shading...Right now, the pic is a little greyed out.
But dang--your technical skill here? MARVELOUS. (applause.)
Good lord, that is beautiful. The background really blows me away... It really gives the impression that they're soaring. The characters themselves are also looking good. The gryphon's back leg looks a tad short.