Created by the Mechanist, tankbots were originally meant to help the people of the Commonwealth as part of a fleet of robots that would defend settlements from various threats. However, a logic error made by her robobrain lieutenants led to these robots becoming hostile to everyone they encountered, unleashing havoc in the area.
Tankbots are based on the sentry bot frame and serve as the Mechanist's heaviest minions. True to their origins, they are among the most resilient automatrons, usually rely on devastating long-range firepower to destroy their targets from afar and erupt in a powerful nuclear detonation when destroyed.
The Mechanist's automatrons are cobbled together from a wide variety of components taken from five different robot models. Tankbots usually consist of a robobrain torso mounted on a sentry bot's three-legged chassis and come armed with various heavy weapons.
The cybermech bot have two arm-mounted gatling lasers and has rusty yellow parts fitted on the outside, functioning as further protection. These tankbots are very rare and only spawn when the player is above level 50.
The Quantum bot is the most powerful and rare tankbot in the entire game. On its right arm it has an arm-mounted gatling laser like the Cybermech variant, and on its left arm a tesla rifle. The head is an Assaultron's head laser painted yellow and so is the rest of the body. The Quantum tankbot also has an electric field surrounding its shell, from the Tesla coil upgrade. These tankbots only first spawn after the player character has reached beyond level 75.