Equinan

Equinans were a race of horse-headed humanoids. They were a space-faring race. They utilised a device called the language monitor, a language translator. Worn about the neck, it offered bi-directional translation for the wearer and his conversational partners. Spacemaster was an Equinan rank apparently equivalent to that of Captain.

The Fourth Doctor and Sarah Jane Smith encountered an Equinan spacemaster, Roppy. (COMIC: The Wreckers)