A gallus was a eunuch priest of the Phrygian goddess Cybele and her consort Attis, whose worship was incorporated into the state religious practices of ancient Rome.
Relief of an archigallus making sacrifices to Cybele and Attis, Museo Archeologico Ostiense, Ostia Antica
Funerary relief of an archigallus from Lavinium, mid-2nd century AD, Capitoline Museums, Rome
Statue of a gallus priest, 2nd century, Musei Capitolini
Attis was the consort of Cybele, in Phrygian and Greek mythology.
Galli
…A gallus (pl. galli) was a eunuch priest of the Phrygian goddess Cybele (Magna Mater in Rome) and her consort Attis, whose worship was incorporated into the state religious practices of ancient Rome. Cybele's cult may have originated in Mesopotamia, arriving in Greece…
Statue of Attis from Roman Hierapolis
Statue of a reclining Attis at the Shrine of Attis in Ostia Antica near Rome.
Attis wearing the Phrygian cap. Terracotta thymiaterion at the Louvre from Tarsus