Watch List notes:

ASIA MINOR, Uncertain. 5th century BC. AR Obol(?) (8.5mm, 0.78 g, 7h). Bearded head of male right, wearing uncertain headdress / Forepart of bull left within incuse square. Numismatik Naumann 58, lot 113; otherwise, unpublished in the standard references. A little off center on obverse, struck with worn reverse die. VF. Extremely rare.

If the obverse head is wearing a crown, it is likely a portrait of the Persian Great King.