The ornamental design for a St. Christopher theme medallion, as shown and described.
FIG. 1 is a front view of a St. Christopher theme medallion; and,
FIG. 2 is a view of the backside of the St. Christopher theme medallion provided with a self-adhesive backing.
The medallion consists of a thin embossed stainless steel plate showing on the front side a St. Christopher theme and being provided at the backside with a self-adhesive foil.