The Bad Batch: 10 Things We Learned From The Trailer
3. Dark Troopers
Dark Troopers were experimental combat droids created as part of the Galactic Empire's dark trooper program. Early iterations were actually body suits worn by a human pilot, until the human element was removed, viewed as the final obstacle.
Up until their debut in The Mandalorian under the command on Moff Gideon, the Dark Troopers had been omitted to Legends. The Ghost crew did encounter a similar droid on board an Imperial Cargo Freighter in Star Wars Rebels, however these droids were never named as Dark Troopers, but as Sentry Droids - although they were clearly inspired by this fan favourite.
In the Bad Batch trailer, we see what looks like an early iteration of the Dark Trooper being used as part of a Clone training exercise. They have the same colouring and markings as the training droids used on Kamino, and could have been introduced as a potential new Separatist variant.