In the 1992 Tokyo Toy Show prototype of
Phantasy Star IV, there was a scene that featured Rune, Chaz, Rika, and Wren in stills similar to those we can see in the final game. This sketch is the basis of Wren's appearance in the scene. Out of the four character sketches like this, the Wren piece is clearly the most unfinished version. They only bothered to draw half of him! I suppose they would have just mirrored the completed half to create the other side in the final sprite artwork. I have no idea what that thing on his back is supposed to be, however.

You may view the gallery page for
Prototype: Wren.