Cubimals (portmanteau of "cube" and "animals") were an in-game collectible from Glitch. The game has shut down, but the former players continue to love Glitch memorabilia. This is a working version of the frog cubimal, which will spin the propeller when the key is turned.

Youtube video of some sweet propeller action! http://www.youtube.com/watch?v=LYvDjvXh2CA

Information about the collectible in Glitch - http://www.glitch.com/items/collectibles/cubimal-frog/