Rahnius

Ambassador Rahnius, or Rahni as he was called by his friends, was an ambassador for the Galactic Alliance. His identity (and likely his skin) was taken by a member of the Slitheen family to fool Sarah Jane Smith. (TV: From Raxacoricofallapatorius with Love)

Behind the scenes

 * Rahnius — specifically, the Slitheen impersonating him — makes note of the fact that he and Rani Chandra share the same first name, uttering the phrase, "the two Ranis". This is a reference to The Two Ronnies, the famous comedy series that starred actor Ronnie Corbett, who portrayed Rahnius.