Olla

Olla was a female Dreilyn who briefly travelled with the Doctor as his companion.

Olla had been the consort of the Vachysian warlord Skaroux until she stole his money and went on the run. (DWM: Redemption) She was on A-Lux when Ice Lord Arryx launched his plans to turn the planet into a snowy wasteland. Soon afterwards, she encountered the Doctor and his companion Frobisher, and helped them in defeating the Ice Warriors. When Frobisher decided to stop travelling with the Doctor and remain on A-Lux, Olla asked the Doctor take her back to her people, thus becoming his newest companion. (DWM: A Cold Day in Hell)

While Olla acted as the Doctor's servant (a role he was not comfortable with), the Doctor's TARDIS was attacked by a Vachysian ship commanded by Skaroux, who demanded that he turn Olla over to him. At first Olla claimed that she had been Skaroux's slave and that he had been a cruel master, but the truth eventually came out. The Doctor handed Olla over to Skaroux on the condition that she would be given fair trial. (DWM: Redemption)