The EVO Troopers (standing for Environmental) represented a specialized class of stormtroopers, functioning as support personnel or operating in dangerous environments. At the core of this specialized group were stormtroopers who harbored animosity towards Non-Humans. They carried FA-3 flechette launchers as their primary weapon. Eventually, they were replaced by a superior unit known as the hazard stormtroopers.
EVO troopers, having undergone specialized training and equipped with significantly enhanced armor including breathing tubes, possessed the capability to endure and function within the most perilous environments, including intense heat, acidic rivers, and electrical storms. While they were typically armed with FA-3 flechette launchers, some also utilized T-21 light repeating blasters and E-11 blaster rifles.
The majority of EVO troopers were drawn from the ranks of stormtroopers who demonstrated a strong dislike for Non-Humans, which resulted in them being more aggressive towards the alien species population they encountered on hostile worlds. EVO troopers could be found in any location where extreme environmental battlefield conditions prevailed; some were stationed on the science vessel ISS Empirical, as well as on Kashyyyk, Felucia, Raxus Prime, and even the still-under-construction Death Star. Ultimately, they were succeeded in their role by the Hazard stormtroopers.