Raxas Alliance

From Tardis Wiki, the free Doctor Who reference

The Raxas Alliance is an interplanetary union comprising four planets: Clom, Clix, Raxacoricovarlonpatorius and Raxacoricofallapatorius. As Clom and Raxacoricofallapatorius are in the same system, it is possible that all of these planets are. (SJA: The Gift)

Raxacoricofallapatorius and Raxacoricovarlonpatorius have similar names and Clom and Clix have similar names also. It's possible that the four planets are made up of two duos.

Since the Raxacoricofallapatorians and the people of Clom share similarities, Clix and Raxacoricovarlonpatorius may have similar lifeforms to each other and the other two planets.