Half Buffalo Pony Foals

[SkyPie 259]

I've recently decided to make the ocs I based off my little half sister and brother half buffalo, since they are half Native American in real life. The thing is I am having trouble envisioning the perfect blend of unicorn and buffalo. I can't even draw a stick figure good, much less a detailed picture depicting these unique creatures. So I was wondering if any artists could help me out. Here's my idea of what they would look like.

My sister is 11, so you can decide how big she would be at that age. She has a bit of a hump from the buffalo but it's not very noticeable. She has the general build of a pony. She still has a hint of an orange brown in her thick, light brown buffalo coat because she had that shade when she was born, as other young buffalo did.  Her legs are pony legs but at the end of each one is a buffalo hoof. Her muzzle is a pony muzzle and her only horn is a buffalo horn, but it sprouts from her forehead in the shape of a unicorn horn. It still has a sharp end. She has buffalo ears and is a bit bigger than foals her age. She has sky blue pony eyes. She has a straight, long pony tail the same shade of her coat but doesn't have a mane.

My 10 year old brother is twice his older sister's size, with a thick, sunset orange buffalo coat, a bit of a curly, ruby red mane on top of his head, and a ruby red buffalo tail. He has sort of a mix of a buffalo and pony build and has a more noticeable hump than his sister, but it's only half as large as a full buffalo. He has pony ears, legs, and a buffalo muzzle. He has two unicorn horns on the sides of his head, in the shape of buffalo horns with blunt ends like unicorns. He also has sky blue pony eyes.