The five little ghosts! - White, Glow In The Dark Opaque, sold between 1990 and 2002. One of my first minifigures, it was offered to me in Alabama in 1990. So it's very special to me! - The tran-clear, red and black, from 1989 and which is are test minifigures for the new molds that would be used later. - And the green, Glow In The Dark Trans, sold only in the set 10176 in 2006. It's much brighter in the dark compared to the opaque version. There are also a yellow version and a series of six other ghosts using the same mold. This series of six was used to analyze the diffusion of plastic. A transparent plastic was first injected in smaller and smaller quantities on each minifigure. Then yellow plastic was injected. The first minifigure is almost trans-clear and the last almost yellow. These are literally impossible to find!