The Bebryces () were a tribe of people who lived in Bithynia. According to Strabo they were one of the many Thracian tribes that had crossed from Europe into Asia, although modern scholars have rather argued for a Celtic origin.
Name
Classical linguists considered the name of Bebryces related to the Thracian Bryges, who were later renamed Phryges (Phrygians), based on the geographic proximity, as well as the migration route of the Phrygians known from ancient myths.
B. Sergent suggests that the name Bebryces could be related to the Celtic tribes Bebruces, living in the Pyrenees, and Bibroci, dwelling in Britain, all ultimately stemming from Proto-Celtic *brebu ('beaver'; see Gaulish bebros, bebrus, Old Irish Bibar, 'beaver'). Ivan Duridanov also suggested that the ethnonym was related to Indo-European words meaning "beaver".
The same word denotes beaver in Slavic Languages (*bebrus in Proto-Balto-Slavic, bober in Slovenian, bobar in Bulgarian, bobr in Russian).
Mythology
According to legend they were defeated by Heracles or the Dioscuri, who killed their king, Mygdon or Amycus.