Tain

Tain was a sentient bioship created by the Makers.

Biography
Tain broke free of Maker control and destroyed its communication organ. It then tried to integrate itself into the surface of Espero to prevent the Makers or their enemies the Oon from taking it back to war. Tain further created the Night Beasts in order to protect itself. Tain was attacked by Reo, who implanted his conciousness into Tain. With the help of the Eighth Doctor, Tain was able to escape his body and enter the body of a Mokey called Tlussus. The Doctor then destroyed Tain's old body and Reo at the same time. (EDA: Halflife)