Osyraa (Janet Kidder) was a female Orion and the leader of the Emerald Chain in the late 32nd century.
Prior to 3189, following Ryn's attempt to rally the people to rebel against Osyraa, she had his antennae hacked off and sent him to her nephew's salvage yard on Hunhau, where he was forced to implant control devices on the slave laborers, becoming a pariah.
In 3189, after learning of Emerald Chain vessels encroaching on the Sigma Draconis system, Fleet Admiral Charles Vance noted that Osyraa was becoming "more brazen by the day."
Several weeks later, Osyraa directed the Emerald Chain toward Argeth, a Federation planet, for reasons unknown to Starfleet.
Eventually Osyraa confronted the Discovery while in command of the warship Viridian.