Bash bots are enemies in Up Your Arsenal encountered in challenges in the Annihilation Nation on Station Q9. They are melee counterparts of the laser bots that attack with a flail attached to their arms.
The basic blue variants are seen in the challenges during the first visit to Annihilation Nation for "Win the Tyhrra-Guise". The dark grey variants, seen in the challenges after the second visit for "Meet with Courtney Gears", deal and sustain more damage. In the gauntlet challenges, they will either spin around and move in a fixed direction, and in arena challenges, they attack by moving towards Ratchet and swinging their flails.
Bash bots pose a moderate threat in most challenges, as they are tougher than gladiators. Though their melee attacks deal considerable damage, they are easy enough to avoid when destroyed from a distance. Like all arena enemies, they will often cluster up, and it is possible in some cases to get them to accidentally damage other enemies while aiming at Ratchet. In clusters, it is good to defeat them with area-of-effect weapons such as the Plasma Whip, Nitro Launcher, and Agents of Doom, or any sufficiently available weapon of your choosing.