itch.io

I thought the same thing! I think that character is designed by a backer. In Morningdew, there was a patreon promotion where if you donated certain amounts you could have something featured in the game. The highest tier reward was to design a character that would give something to the main character throughout the game. 

So I imagine the same happened here. Seems that backer puts a lot of funding into these games! I can't blame them here, the game looks so good, I can't wait!