Good and demented
I have never heard of a questing beast before, but I can see why you like it so much. There are just so many mythical creatures out there it's great you support one of the underrated ones. This design is fantastic because there are so many vibrant colors being used. It could have used a background but that's really it in terms of flaws. I can make out at least one eye on the purple neck (or whatever body part it is). It seems to be a hybrid of a snake, wolf, and a horse.
I guess you can come up with tons of different kinds of hybirds, eh? At first I thought the little red dots on its skin was supposed to be warts. Looking closer, I'm fairly certain it's actually it's fire coming out of its pores. I also like how it seems to have a sword literally hooked up to its body. There's also a cloak or some clothing on that hook.