Collector General

The Collector General is the command-and-control unit of the Collectors in Mass Effect 2. It appears very different to its minions, having no humanoid shape but a large, bulbous, multi-limbed body akin to an insect or a crab. It commands its Collector drones from afar, deep within its stronghold at the galactic core, and only makes its presence known to Shepard and the Normandy crew by possessing drones in the field.

Mass Effect: Redemption
Following the destruction of the SSV Normandy, the Collectors sought to acquire the body of Commander Shepard. Shepard's corpse had been recovered by agents of the Shadow Broker, an enigmatic individual who controlled the galaxy's largest information network. The Collector General sent its drones to negotiate a deal with the Broker to retrieve Shepard's body.

The eventual exchange was made on the Broker's base on Alingon with the Broker's personal enforcer Tazzik. Everything was going well, until one of the Broker's agents, Feron, walked up to say that the Broker wanted full payment upfront. The General, controlling a Collector intermediary, refused to pay until it had verified Shepard's identity personally. However, Tazzik was willing to believe Feron. At that moment, the Collector General, speaking personally with the Broker, accused him of betrayal. The Broker defended that Feron wasn't speaking for him and with his communications disabled on Alingon, he could not inform Tazzik otherwise. The General, displaying its greater omnipresence, revealed through its drone that Feron was a traitor. However, Liara T'Soni, who was working with Feron, was able to escape with Shepard's body, taking it far from Collector hands.

Mass Effect 2
After failing to acquire Shepard's body, the Collector General organised several attacks on human colonies across the Terminus Systems, abducting their entire populations. Its intention was to carry out the harvest of the human race before the Reapers began their next invasion, preemptively eliminating a significant threat. The thousands of captured humans were taken to the Collectors' base at the galactic core where they were processed, broken down into raw genetic material used in the construction of a new Human-Reaper.

The Collectors' activities soon drew the attention of the human-supremacist group Cerberus which had acquired Commander Shepard's body and used their extensive knowledge and resources to bring the Commander back to life. Shepard and the crew of the Normandy SR-2 took the fight to the Collectors, travelling through the Omega-4 mass relay and invading their base of operations.

The General rallied every available Collector drone to protect the base, and possessed multiple drones during the battle, but the tactics used by Shepard's fire team caused it to spread itself too thin. Shortly before the sabotaged base met its end, Harbinger, after berating the General for its failure and asserting the Reapers "will find another way", released its control over the Collector General, whose eyes lost their glow for the first time, suggesting that it was always under Harbinger's control. In the final seconds after being released, the Collector General appeared to be confused or dismayed at being abandoned, suggesting some level of intelligence and emotional capability remained. The General is then killed when Shepard either destroys the Collector Base or activates a timed radiation pulse, killing all remaining Collectors on the base.