Maximinus Thrax AE25 of Dium, Thrace.  

obv: IMP C C IVL VER MAXIMINVS. laureate, draped bust right 
rev: COL IVL DIENSIS D-D, Athena in crested helmet, standing left 
with patera & spear, serpents at sides. 

Moushmov -, Varbanov -, SNG Cop -.

Reverse is unlisted for Max Thrax in both Moushmov and Varbanov,
but there is an Athena reverse listed for many other rulers (Julia Soaemias, 
Geta, Caracalla, Salonina, Septimius Severus, Hadrian, Domitian, and Augustus) 
so it's a reasonable candidate for an unlisted type!

Contributed by Gary Leonard, March, 2003.