The five Protectobots - Hotspot, Blades, Streetwise, Groove, and First Aid - made their first appearance aiding the Autobots in saving humans from the Insecticons and their clones, who were attacking a city en masse. However, as the Protectobots went about their work, meanwhile, on Cybertron, the traitorous Combaticons had arrived, and easily overthrown Shockwave, taking control of the planet. Reprogramming the Decepticon spacebridge, their leader, Onslaught, manipulated the orbit of Earth, to send it into the Sun. As the effects of the increased proximity to the Sun were felt on Earth - fires and death through exposure, and so forth - the Protectobots did their best to save lives and prevents catastrophes, as a small contingent of Autobots, teamed up with some Decepticons travelled to Cyberton and put a stop to the Combaticons' plans.

When Megatron reprogrammed the Combaticons to be loyal to him, they clashed with the Protectobots. After the Combaticons merged into their gestlat form of Bruticus, the Protectobots revealed that they too had that power, and combined into Defensor, besting Bruticus.

The five Protectobots have their own individual powers and definitive personality traits. Save for Hotspot, they are armed with blasters which fire bursts of high-level intensity light to blind their enemies. They combine into the giant robot called Defensor.

HOTSPOT

Leader of the Protectobots, Hotspot transforms into a blue fire engine. Why he is blue, in contradiction to common Earth fire engines, is unknown. He is a skilled leader and fighter, respected by his Protectobot comrades. He is armed with a fireball cannon, and forms Defensor's torso.

BLADES

Blades is the gung-ho member of the Protectobots. He loves to fight, but the fact that he transforms into a helicopter, meaning he remains in the air much of the time, irritates him. He finds aerial attacks cowardly, but still does his job well. He forms Defensor's right arm.

FIRST AID

First Aid is a pacifist, and despises war and fighting of all kinds. He is the medic of the Protectobots, and took on that role for all the Autobots after Ratchet's death. He can emit a high-intensity laser beam from his fists which he uses for welding in surgical procedures. He transforms into an ambulance, and forms Defensor's left leg.

GROOVE

Groove would rather be relaxing than fighting. He's the easy-going member of the Protectobots, and, like First Aid, dislikes war and violence. Resembling a motorcycle when transformed, he is a daydreamer, with a short attention span, which often causes problems when the team merges into Defensor, when Groove forms the right leg of the gestalt robot.

STREETWISE

Streetwise pays enormous attention to detail. With his great capacity for understanding, he easily adapts to any environment or situation, quickly and decisively knowing what to do and when to do it. He transforms into a police car, forming the left leg of Defensor.

DEFENSOR

Defensor is the gestalt form of the Protectobots, the last of the initial wave of gestalt teams. Defensor is dedicated to the protection of all life, and is capable of generating a protective forcefield in a fifty foot circle around him. However, this uses up tremendous energy, so Defensor rarely uses it for extended periods of time. Defensor suffers from poor circuit connections, which often make him slow and sluggish. Occasionally, the portion of his mind that is Groove's wanders, causing brief mental lapses within Defensor.

The Protectobots were not present at the Autobot City Massacre, but they were seen numerous times throughout 2006, managing and operating from the repaired city, now known as Metroplex. First Aid became the head of medical operations at Metroplex. On one occasion, the Combaticon, Swindle, stole Metroplex's transforming cog, rendering him helpless. Believing himself to be of no use to the Autobots because of his pacifist beliefs, First Aid left them for a short while, but was convinced by Hotspot to return, and to help realign Trypticon's cog (which the Autobots had stolen and installed in Metroplex) so that Metroplex could transform and beat the Decepticon city. The status of the Protectobots following the restoration of Cybertron's Golden Age is unknown.