BETELGEUSIANS

Betelgeusians are an advanced  space faring humanoid species native to the Betelgeuse planetary system, and known to inhabit at least two of the system's planets: Betelgeuse V and VII. Betelgeusians have strange familial structures, including multiple mothers and some sort of relation known as semi-cousin.They are known to sometimes get extra limbs and even heads attached to their body.
Source: The Hitchhikers's Guide to The Galaxy