A: Sarapis enthroned, to left, wearing tunic and mantle, with a tall scepter in the left hand. Right hand extended over the three-headed Cerberus. Above his head: a scarab with outstretched double wings, around: Ouroboros with head at top, to right.
B-C: Inscription in eight lines on the reverse, with the last two letters written as a ninth line on the edge: ιαωαν|αραβα|ραναωαι|σθομβαο|ληβαολσ||θομβαλακα|μοθομ|βα|λη → palindrome including Ἰάω, variant of the σθομβαολη-logos.
Bibliography
Bonner, SMA on CBd-1284
The Kelsey Museum Artifacts Database on CBd-1284