Anagram
From Tardis Wiki, the free Doctor Who reference
An anagram was a word or phrase created by rearranging the letters of another word or phrase.
The Mimic's inability at original thought caused it to use anagrams. When it merged with Francis Pearson, it used the names Persona and Sperano, both anagrams of Pearson's last name. Even the name it became known by, Managra, was an anagram of 'anagram'. (PROSE: Managra)
Behind the scenes
Roy Tromelly was a pseudonym used to conceal the identity of actor Terry Molloy in TV: Remembrance of the Daleks, so as not to spoil early that the Emperor Dalek was in fact Davros. It is an anagram of Molloy's name.