The Praxilions looked like red and white striped caterpillars. They stood upright by bending into an "L" shape. They were unable to use technology designed for humanoids. Praxilions had three genders: male, female and one translated as sculptor.
The Praxilions evolved long after the EMTT, and lived a simple farming life. When Edwina McCrimmon was transported to Praxilion by a time rupture, she became their queen and moved them into a period of rapid industrialisation. This industrialisation attracted the Consolidator, a Time Lord ship containing dangerous species and technology. The Sild tricked them into releasing them, and the Sild proceeded to ravage the planet. (PROSE: Harvest of Time)