Kiddo misspoke and said "octocorn" instead of unicorn and I couldn't help myself.

BEHOLD THE UNHOLY ABOMINATION WROGHT BY MY UNPARALLELED EDITING SKILLS

I love this as a fantasy creature idea

Yeah me too, can't say I've seen this kind of a horse chimera before.

Reminds me of a jackalope.

Good news! It's open source! Feel free to add subtract or change it to your fantasy game setting as needed or desired!

Styracosaurus?

I was trying to place it myself.

Whoops, looks like I'm wrong. Your photo not of a Styracosaurus, but rather a Kosmoceratops.

Cool! Give him a thagomizer too! Then give your kiddo the secret word to tame him and ride him to adventures!