Caracalla. Serdica, Thrace. 

Obv: AVT K AV CEV ANTWNEINO, laureate head right
Rev: C-EP-DWN, described as "two playing Erotes, the one walking on his hands" (SNG Copenhagen, whose example shows less detail); "Two Erotes playing leapfrog with one Erote holding the other's foot" (Riggauer), "Two Erotes engaging in anal intercourse to the right" (Numismatik Lanz) and "Eros winged, naked, holding another Eros by his leg, who is supporting himself by his right hand on the ground" (Moushmov). 

SNG Cop. 801; Winterthur 1258; L. Ruzicka, NZ 48, 1915, 62 Nr. 380. Very rare. 

Numismatik Lanz, Auction 144, Lot 564, Ending November 24, 2008. Estimate: 4000 EUR. Lot unsold.