It's a boat. A low quality horizontally rotating boat. Have fun with it. Remix and make different boats.
Thanks to @LEG0master for the idea and some of the code from their project: 3d boat Devlog: 1.1: It's finally done! 1.2: Added flying boats (spaceship compatibility) 1.3: Added more boat remixing compatibility (repeat (i) stack costume (costume) xy (x) (y))