Aplan

Aplans were the native inhabitants of the planet Alfava Metraxis.

Biology
The Aplans were humanoid lifeforms with two heads. The heads apparantly had their own seperate intelligence and personalities as, for in at least one period, heads were allowed to marry each other. (DW: The Time of Angels)

Culture and History
According to the doctor they were a relaxed and described them as relaxed and cheerful, and he thought them a wonderful species. They practiced religion, building temples and burying their dead in Aplan Mortaria (sometimes known as Mazes of the Dead), which were designed to alow the dead Aplans to ascend into the afterlife. Some of them practiced Self marrying, until their church forbade it. They were fastidious at recordings their social, cultural and political history.

The Aplan civilisation came to a mysterious and abrupt end in the mid 47th century. This was revealed to have been caused by the Weeping Angels, which infested the dark underground Mazes, well hidden amid the numerous statues. (DW: The Time of Angels)

The Aplan were also described as prolific builders, and by the 51st century all that remained of them on their home planet of Alfava Metraxiof were buildings from the Tranolite Period of their history,

Trivia

 * The Aplans may be a reference to Douglas Adams' two headed character Zaphod Beeblebrox from The Hitchhhiker's Guide to the Galaxy. Adams was also a writer for Doctor Who.