If you use the command: /tp @e[ type=Pig ] @e[ type=??? ] (without the weird spaces) on a powered repeat command block to teleport a Saddled Pig to another entity, while a player is riding the pig, it will produce a visual glitch of the pig & player being teleported once every few seconds. This visual bug will get even more random if the mob the pig is being teleported to, is flying (e.g. Bat, any Mob on a leash mid-air), as visually, the Pig normally only gets teleported when the mob is flying one block above the ground, or in rare occasions, when the mob is in mid-air, meaning the Pig will remain on the ground for a much longer duration then normal.
In a similar vein to this bug, there is another bug, when using the /tp command on a powered repeat command block to teleport any mob to a flying mob (e.g. a Bat), the mob will visually be floating under the flying mob instead of floating inside the flying mob.