Halassi

The Halassi were a species who owned the Halassi Androvar.

When King Hydroflax visited their planet, the diamond was driven into his skull, and the Halassi tasked River Song to retrieve it.

A crowd of them were present on the starship Harmony and Redemption. They sent Scratch to procure the diamond, but River refused to give it to them as it was still in the head of Hydroflax. They surrounded the Doctor and River but they escaped. (TV: The Husbands of River Song)