L1

The L1 was a service robot used by Drathro in Marb Station on 2,000,000,000 CE Ravolox. The robot was tank-like and equipped with a camera, search light, tentacles, and a tracer disc. It could climb up stairs on its treads and it was capable of crashing through rock walls.

L1 was sent to capture the Doctor and bring him back to the Station to repair the black light converter that powered Drathro and the Station. While trying to bring him back, however, the L1 was ambushed by Katryca and her warriors who, thinking he was the Immortal(meaning Drathro), destroyed him with their guns. (DW: The Mysterious Planet)