Like most sandbox games, 2007’s Assassin’s Creed gave you access to a horse that could help you get around the map more quickly. What you might not have known, though, is that Altair’s steed was in fact a human skeleton that Ubisoft’s engineers had stretched out and transformed into a horse due to the developer’s tools only supporting bipedal characters.

“The horse in AC1 was just a twisted f***ed-up human skeleton because our tool chain only worked with biped in 3ds max,” former Ubisoft developer Charles Randall tweeted. “Cheers to the amazing animators and riggers that managed to make that guy look like a horse!”

Randall also shared a few other non-nightmare fuel stories from the development of Assassin’s Creed. For the character of Malik, who only had one arm, Ubisoft didn’t have the budget for a custom skeleton so the solution was to turn his extra limb inside out and push it up into his abdomen. “I assume if you could get the camera to clip into him you’d see a tiny little scrunched-up arm inside the bicep,” Randall tweeted.