Not sure what it would look like or how it would work physically...
Lila's Delcatty in Battling the Generation Gap!
The Wild Togepi in Where No Togepi Has Gone Before!
Professor Juniper's Accelgor in Evolution Exchange Excitement!
Shaymin (land form) in Giratina and the Sky Warrior
Generally speaking, it makes an exact copy of the user (an afterimage) and once the copy is hit it dissapears.