In one parallel universe, a version of the Doctor was pursued by the Time Lords. He commited suicide by jumping off a pylon in an attempt to avoid capture, and in the process regenerated into a female. The Doctor then began to hide on Earth.
In this universe it was against the law of the Time Lords to regenerate into a different gender. (AUDIO: Exile)
This dimensions War Lord and his people were dematerialised by the Time Lords.
Other alien races that were mentioned to have appeared included the Quarks.