Wrax was a barren planet that, due to fluctuations in history caused by the Kotturuh crisis, became a jungle planet and home to the Wraxian race.

The Eighth Doctor and the Dalek Time Squad visited Wrax to determine the origin of the fluctuations, where the Dalek Executioner used the Devolver to reduce the Wraxians to proto-plasm. (AUDIO: The Enemy of My Enemy)

Later the Master visited Wrax and obtained the Devolver. (AUDIO: Master Thief)

Ultimately, history was put back on its proper course, when the Dalek plan to destroy Gallifrey was foiled, and Inyit, the last of the Kotturuh, transferred the last of her energies into Ikalla. (PROSE: All Flesh is Grass) How this affected the fate of Wrax currently remains unknown.