#25 Scorpion Droid
When the droids redesigned themselves into new bodies during the droid wars, human psychology played a significant role in the resulting form. The machines didn’t want a form that just functioned, they wanted a form that would be intimidating, decimating their human enemies emotionally before anyone ever pulled a trigger.
A 14-foot long metal scorpion does that quite nicely.
Beyond the form, though, the Scorpio is a combat droid that is equipped with shield generators and a mean set of claws. It has no projectile payload simply because the machines felt the maneuverability, efficient stabbing weaponry, and sheer fear factor made it an effective enough ground combat droid.
The machines don’t like to waste resources, like extra guns, if they don’t have to.