This is a bug for ALL devices. It is where if you put many minecarts together while they're moving it will glitch into one out-of-shape minecart. If you release this Glitched minecart off of its rails and push it in a direction it will drive itself in that direction without rails until it reaches something that blocks its path. Sometimes it will go in that direction in mid-air until something blocks it and it falls. This glitch can be preformed with a player or animal in it and without.