Palare

Palare (pa-lar-ree) or Polari was the language developed and used by carnival people and other travelling entertainers. Ace could speak and understand parlare, including swears. (PROSE: Love and War)

When Vorg spent time on Earth, he picked up some of the Palare. When he met the Third Doctor, he believed he was also a showman and attempted to speak to him using the Palare. (TV: Carnival of Monsters, PROSE: Doctor Who and the Carnival of Monsters)

Jacquilian and Sanki spoke primarily in Parlare. Mike Yates, Alexander Shuttleworth and Forgwyn could also speak it, and Bernice Summerfield was fluent, considering it "basically what her mates spoke". (PROSE: Happy Endings)