Echo, formerly designated CT-1409 and known as the Hero of Anaxes, was a genetically defective human male clone trooper veteran Clone Corporal and former Advanced Recon Commando of the elite 501st Legion who served as a CT-99 clone commando of the elite Clone Force 99 in the Grand Army of the Republic during the Clone Wars.

The 501st Legion, also known as Vader’s Fist, was an elite unit of clone troopers in the Grand Army of the Republic during the Clone Wars. They were known for their blue markings and their close association with Jedi General Anakin Skywalker and Commander Ahsoka Tano. The 501st played a significant role in many battles and were instrumental in the execution of Order 66, turning on the Jedi. They later became a prominent stormtrooper unit in the Imperial era.