Hop Pyleen

The brothers Hop Pyleen were two wealthy brothers who attended the destruction of Earth in the year 5,000,000,000 on Platform One. They were two reptilian humanoids from the clifftops of Rex Vox on the planet Rex Vox Jax. The pair became famous and rich due to inventing the Hyposlip Travel Systems. They preferred to wear fur clothes to keep their cold-blooded bodies warm. (DW: The End of the World)

The brothers, along with the other surivors of Platform One, were later kidnapped by the Elth of Balhoon, who believed that they hadn't tried to help the Moxx of Balhoon and had abandoned him to die. They were rescued by the Doctor, and not only forgave the Elth for kidnapping them, offered to help him. (DWBIT: Reunion of Fear)