Petyr was a crusader of the Second Revelation droid freedom group who searched for similarly enlightened sentient droids within the Galactic Empire between 3 ABY and 4 ABY. An MSE-6 series repair droid of small stature but regarded as a large and virtuous soul by the crusaders' leader, Ajax Sigma, Petyr rushed to report the initial outbreak of the Scourge, an invasive mind-controlling malady linked to the Scourge droid consciousness. Although Petyr was possessed by the Scourge while aboard an Imperial Star Destroyer near the Amaxine Space Station, the Second Revelation was alerted to the plague by Petyr's desperate message.
The Scourge later used Petyr's droid body to infiltrate the Rebellion with infective spider-droids, controlling the rebel droid C-3PO. Under the Scourge, Petyr and C-3PO's bodies then attempted to assimilate the Force-wielding cyborg Darth Vader on the planet Mustafar, but their assault was unsuccessful. Meanwhile, the Second Revelation used Petyr's information on the Scourge to attack its Star Destroyer and failed as well, but Ajax Sigma joined D-Squad to attack the Scourge again with information from Petyr's sacrifice and ended the galactic threat.
Petyr was an MSE-6 series repair droid of the Second Revelation, a group of sentient, freedom-loving droids. As an undercover crusader, he searched for similarly enlightened droids in the Galactic Empire. Petyr was aboard the bridge of the Chelator, an Imperial I-class Star Destroyer that was sent to the Amaxine Space Station between 3 ABY and 4 ABY when the Scourge malady infiltrated the vessel before it could depart the station's vicinity. The plague infected droid minds and assimilated them into the Scourge droid consciousness, which was intent on possessing more droids. The afflicted droids then killed surrounding sentient organic beings; Petyr witnessed the entire organic bridge crew succumbing to poisonous gas unleashed by the infected droid crew.
Upon finding the human bridge crew dead, Petyr sped across the Star Destroyer, passing through a hangar via a narrow overhead passageway when the Scourge cleared the hangar's officers, stormtroopers, starships, and equipment by exposing it to the vacuum of space. Petyr then weaved through corridors filled with the corpses of more officers and troopers and eventually found a wall socket interface, extending a data probe to reach it.
After quickly sending a desperate warning to the Second Revelation about the Scourge, Petyr drove away from the socket and was attacked by an even more diminutive spider-droid from the Amaxine Station—all other droids aboard the ship had been infected by the Scourge's spider-droids. Petyr extended his four arms to fight off the assailant's three claws over him, but the spider-droid was able to close their distance and attach to the MSE-6's boxy body, allowing the Scourge to possess Petyr.
Petyr's message was received in the Second Revelation's colony by the aide Gertee, who relayed the warning to the movement's leader, Ajax Sigma. Initially hopeful for a discovery of an enlightened droid, Sigma expressed pity for Petyr's fate upon learning about the Scourge and resolved to destroy it. On the Chelators bridge, Scourge's 3PO-series protocol droids placed diminutive spider-droids inside the droid bodies of Petyr and several other MSE-6 units, using them as vectors for spreading the malady.
The MSE series droids made their way to a hangar and each of them boarded a Lambda-class T-4a shuttle—after the shuttle ferrying Petyr exited hyperspace, the droid drove off its entry ramp into space and the shuttle entered hyperspace again. The droid subsequently reached a fleet of the Rebel Alliance and secretly boarded an EF76 Nebulon-B escort frigate, allowing the Scourge to corrupt the protocol droid C-3PO. The MSE unit remained beside C-3PO in a hangar of the rebel flagship Home One when the hybroid Lobot lost control of his mind to his implants and sent the ship's systems out of control. Using C-3PO alone, the Scourge later learned about the Force energy field by speaking with the rebel human Luke Skywalker and ejected the rebel astromech R2-D2 into space before the protocol droid rejoined Petyr, whose spider-droids had assimilated other rebel droids, on a rebel CR90 corvette. The corrupted droids caused havoc across the rebel fleet, and C-3PO and Petyr commandeered a Taylander shuttle from a larger vessel amid the chaos.
The Scourge wanted to possess the Force-wielding cyborg Darth Vader on the planet Mustafar. Willing to risk losing C-3PO and Petyr for that goal, the Scourge landed the pair's shuttle near Fortress Vader, the Empire's Mustafarian base. The mouse droid climbed a dirt path up to the castle and entered it via a small secret entrance, returning sensor data of Vader's dark corridors that was unfamiliar to all of the Scourge's droids minds. Nevertheless, it unleashed a spider-droid upon finding a group of several DT-series sentry droids. The mouse droid and a pair of sentry droids then broke into Vader's bacta tank while he was submerged inside.
Around the same time, Sigma announced to a team of his crusaders that, using the designation of the Scourge's Star Destroyer provided by Petyr, the warship had been tracked by "other visioned agents." He thus led a group of droid revolutionaries to stop the Scourge, dividing its attention. With the Scourge's focus diverted from subduing Vader, the weaponless Sith Lord used the Force to destroy the sentry droids and the spider-droid carried by Petyr. Despite the Scourge's failure to assimilate the cyborg Sith Lord, Sigma was the sole survivor of his attack on the Scourge, which continued spreading throughout the galaxy.
Nevertheless, the droid revolutionary attacked the Scourge again with D-Squad, a unit of droids comprising the astromechs R2-D2 and QT-KT, the bounty hunters 4-LOM and IG-88, and the assassin droids 0-0-0 and BT-1. Sigma provided imagery from Petyr's sacrifice of signs for the primary entity of the Scourge to the team, who were triumphant in battle against the Scourge on the Star Destroyer, freeing all afflicted droids in the galaxy.
Petyr was a masculine MSE-6 series repair droid made by Rebaxan Columni, standing 0.25 meters tall and speaking in the beeping language of Cruly-3. Petyr worked as a crusader of the Second Revelation, infiltrating an Imperial Star Destroyer in order to find other self-aware droids—a difficult task, given the rarity of such beings. He was deemed a brave and good soul by Ajax Sigma, and the mouse droid rushed to report the Scourge to the Second Revelation when the malady took control of the Star Destroyer. Petyr put up a brief fight against a spider-droid of the Scourge, and the sacrifice of this "fellow brother" was remembered on multiple occasions by Sigma.
Petyr had a gray box-shaped body with several dents and cracks and a triangle with a side that spanned nearly the droid's width indented on both his front and back ends. The front triangle bore a light gray mark left of the bottom point. He moved on four wheels and stored four extendable arms in his chassis—mounted with two claws, a data probe, and a knife—all of which he used to counter the smaller spider-droid's spindly claws. The crusader utilized the data probe to communicate with the Second Revelation via a Star Destroyer wall socket. Possessed by the Scourge, the droid later shot a pair of flexible arms at a rebel frigate's hull, allowing the claws to grab hold of and pull on it to get closer to a port before using an arm to press an adjacent button to gain entry.
Petyr first appeared in the first issue of the Star Wars: Dark Droids comic miniseries, written by Charles Soule and illustrated by Luke Ross. The issue was published by Marvel Comics on August 2, 2023. Petyr is distinguished from other MSE-6 droids in the comic by the triangle markings on each of his two ends. While other MSE-6 droids in subsequent issues of the Dark Droids comic event also bear the triangle markings, this article assumes that only the one that was deployed to the rebellion was Petyr, as shown in Dark Droids 1. That issue is also inconsistent with Petyr's shading, with his body sometimes having black plating while the triangles and side panels colored light gray.