It looks a lot like Skydancer of the '80s cartoon Rainbow Brite, who creates thunder and lightning as he gallops across the stormclouds. That's what I thought when I saw the thumbnail in the gallery But I love the night sky purple-blues and the sprinkling of stars.
Starlite was Rainbow's horse. Skydancer was Stormy's. There was also a third horse, the only female, who was pink with a white heart on her forehead, Sunriser. Oh, and Krys's On-x. I was rather obsessed with '80s cartoons, Rainbow Brite especially, a few years ago...