Perceptor was given no background information in the television show. In season two, he all of a sudden showed up and was treated as if he had always been a member of the Autobot crew that originally crashed on Earth. What I have done here is take elements from various sources and combine them into the background for this important Autobot.
Perceptor continues his role as one of the Autobot's top scientists. He spent thousands of vorns working against the Decepticons on Cybertron. During this time, the Decepticons controlled most of Cybertron, placing many Autobots under the tyrannical rule of Lord Straxus. Autbot resistance was limited to small pocket bands of warriors. Perceptor was commander of one such band containing the Autobots Blaster, Beachcomber, Cosmos, Warpath, Powerglide, and Sea Spray.
The years were filled with vain attempts to attack Decepticon troops and the stronghold at Darkmount. Without an established leader, the Autobots find their situation to deteriorate steadily as their loss mount. Resources dwindle to the point that most supplies come from raids upon Decepticon supply parties. Hidden in the ruins of an old Autbot defense base, Perceptor and his fellow warriors are able to escape Decepticon capture.
Battles rage fiercly until one of the Autbots confiscates a Decepticon transmission originating from a distant planet. From the well-known Decepticon Soundwave, the broadcast pleads for assistance and reinforcements for the Earth-bound Decepticons. They have met with trouble fighting a band of Autobots led by none other than Optimus Prime. The news of Prime's survival and their success against the Decepticons stirs a strong dedication within Percepor. News comes through underground channels that the Decepticons have constructed a Space Bridge that will enable them to transport themselves across large distances.
Realizing what this construction could mean for the Autbots on Earth, Perceptor begins to set in motion an attack upon Darkmount. The battle is costly to both sides, but the Autobots manage to fight their way to the Bridge. Straxus waits upon it, and demands a duel with Blaster. The final battle between Blaster and Straxus ends with Straxus' disintegration as he is tossed over the edge of the Brige into an interdimensional void. However, the conflict has caused the Decepticon Space Bridge to malfuction, and it suddenly activates with Perceptor and his band upon it. The scene around them shifts and changes until they suddenly find themselves standing in the wilderness of an unknown world, Earth.