There are a few out there! Shuppet in particular are rather adorable. ... Most are a little eerie, though...

But... it's a pretty weird range, actually! Back around when I first showed up some teleported people off into the far ends of Johto... Normally though it's more along the lines of turning invisible and appearing where and when you least expect it to get a laugh.

. . . kind of like what actual ghosts are like, I guess.