When I saw this challenge, I decided to go to Wikipedia & just pick a mythological character at random. I dived in at the K's and scrolled down until I saw Kelpie. Now way back when I was in Brownies I was a Kelpie. My friends were all Pixies, Fairies and Sprites so I always assumed Kelpies were something similar. Imagine my surprise when Wikipedia told me that a Kelpie was a malevolent water horse, "said to lure humans, especially children, into the water to drown and eat them". Not unsurprisingly they never told us that in Brownies.
So, armed with polymer clay and only the most catoonish idea of what a horse actually looked like, I bring you the Kelpie.
After a while it started looking like a My Little Pony , so I just went with it. With the red eyes I was going for malevolent, but I think I ended up with something between constipated and sleepy.