The Lakertyans were a race of reptilian humanoids.
Biology
The Lakertyans looked like humans with yellowish skin and scales around the face. They had impressive gold coloured manes. Lakertyans also differed from baseline humans in skeletal structure, with a longer skull and larger vertebrae that included external posterior caudal segments.
Technology
When the Rani came to Lakertya the Lakertyans were primitive but she soon had them operating he machinery. They were unable to devise a way to remove the tethers with which they were fitted, Melanie Bush was able to do so. (DW: Time and the Rani)
History
The Lakertyans were a primitive people when discovered by the Rani. They were enslaved to work on the Rani's Time Brain project. Many Lakertyans were killed by the hard work, the Rani's traps or the Tetrap slave-masters.
Though some of the Lakertyans tried to fight back, the Rani created more threatening motivators, such as deadly insects and electrifying bracelets.
Eventually, the Rani's plan to convert Lakertya into a Time Manipulator was stopped by the Seventh Doctor. This action started the Lakertyans to a path of self-sufficiency. (DW: Time and the Rani)