Ghosts are enemies from Rayman Legends and Rayman Adventures. They appear mainly in Teensies in Trouble, Murphy's Dungeon and Medieval Mayhem.
Ghosts can usually be seen flying around in the Phantom Manor stages, which take place inside old castles. They have a green, glowing color and big white eyes. They have two arms hanging by their sides, as well as two small ears. Fire Ghosts are orange, with a single eye and the same body structure as the normal. They are usually set on flying in one specific direction and tend to only look at where they're flying. Rayman can kill them either by punching or jumping on them, or by using Murfy if it's a fire ghost and the stage allows it.
A ghost peeking up in the background
Several ghosts flying in a circle formation