A sizable, masculine-programmed droid, known as the Great Heep, oversaw a massive fuel ore processing facility located on the planet Biitu. This occurred during the early years of the Galactic Empire. The Heep was an Abominor, belonging to an extra-galactic species comprised of highly advanced, self-replicating droids. These droids had previously enslaved countless organic beings across numerous worlds before being forced out of their native galaxy. Powering the Heep was an internal furnace demanding a continuous fuel supply. It also recharged by siphoning energy from astromech droids. In 15 BBY, the Heep allied with Admiral Terrinald Screed of the Galactic Empire to extract fuel ore on Biitu. This involved the enslavement of the indigenous population and the construction of a "moisture eater" which removed all moisture from the atmosphere to create ideal operating conditions. However, when the "moisture eater" was destroyed by merchant Mungo Baobab and his droids, C-3PO and R2-D2, the accumulated water unleashed a storm that extinguished the Heep's furnace, thereby deactivating the droid.
The Great Heep's existence stretched back far, reaching even before the Imperial era. He served as an agent for the Abominor, an extra-galactic species of sophisticated, self-building droids. These droids systematically exterminated or enslaved organic life forms across numerous planets, plundering their resources. A war erupted between the Abominor and the Silentium, a droid species valuing order over the Abominor's chaotic nature. This conflict allowed the dominant organic species to reorganize and expel both machine societies from their galaxy. At least 300 years before the establishment of the Galactic Empire, the Great Heep was somehow deactivated. His inert form was placed within the Braltzamir Museum of Antiquated Machinery on Coruscant, the capital world of the known galaxy. Admiral Terrinald Screed of the Imperial Navy eventually discovered the Great Heep's display during the early Imperial period. With the assistance of students from the Imperial Engineers Academy, Screed successfully reactivated the Abominor.
The discovery of abundant fuel ore deposits on Biitu, a world in the Outer Rim, in 15 BBY, drew the attention of the Great Heep, the Empire, and Mungo Baobab, the heir to the renowned Baobab Merchant Fleet. Baobab planned to create a mining operation that would fairly compensate the native Biituians. However, the Great Heep sought to enslave the local population and exploit the planet's resources. He formed an alliance with Screed, and together, they seized Biitu and established a droid-operated mining operation. A central element of this operation was a structure called the "moisture eater," which extracted all moisture from Biitu's atmosphere. This created the arid conditions favored by the Abominor and cooled the mining equipment, but it also caused a drought that decimated Biituian crops and brought the farming-dependent natives to the brink of death.
The Heep assumed control of the mines and established a droid harem, where he maintained a large collection of unsuspecting astromech droids. He treated them to oil baths and other droid amenities before draining their energy to replenish his own. Other captured droids were forced to work in the mines under the supervision of the Heep's sludgegulper droids. Droids attempting to escape were recycled as scrap metal. Baobab was captured during the initial invasion, imprisoned, and made to await Screed's arrival. The merchant's droids, the R2-series astromech droid R2-D2 and the 3PO-series protocol droid C-3PO, were also captured by sludgegulpers while traveling to Biitu aboard the Baobab Merchant Fleet starship Argo Moon. R2-D2 was sent to the droid harem, while C-3PO, along with other captured droids, was brought before the Heep. Amused by C-3PO's connection to Baobab, the Heep assigned the protocol droid to work in the mines.
The mining operation soon yielded its first shipment of fuel ore for the Empire, and the Heep met Screed as the admiral arrived to collect the ore and take custody of Baobab. That night, while the Heep recharged by draining energy from the astromech droid KT-10, C-3PO infiltrated the droid harem and warned the other astromechs about the Heep's intentions. Hearing the commotion, the Heep used his magnetic grapple to seize C-3PO from within the harem. As punishment for his defiance, the Heep ordered C-3PO to be dismantled for spare parts. However, C-3PO's warning prompted R2-D2 to escape from the harem. The next day, while processing fuel ore, the Heep spotted the escaped astromech droid. Seeking to recharge from R2-D2, the Heep ensnared the droid with his magnetic grapple, but R2-D2 disconnected the magnet's power cable and fell onto a conveyor belt below. R2-D2 escaped into the ore processing machinery, where he reunited with C-3PO, who had escaped custody before his dismantling. When the two droids emerged, the Heep was waiting and trapped them in a container, which he sealed and disposed of in a laser furnace.
C-3PO and R2-D2 escaped again and joined Baobab after he broke out of his cell. After sending the Biituian Fidge Tadrazan to free the astromechs from the harem, Baobab and the droids attempted to board Screed's ship to destroy the moisture eater. Screed tried to stop them, but R2-D2 escaped in the ship. The Imperials' attempts to shoot it down were hindered by the arrival of Tadrazan and the freed astromechs, who began to attack Screed's stormtroopers. Arriving amidst the chaos, the Heep blamed Screed, who in turn accused the Great Heep of losing control of his droid harem. Their argument ended abruptly when R2-D2 opened the ship's cargo doors, dropping its load of ore containers before opening fire on the moisture eater. Attempting to regain control, the Heep summoned two sludgegulpers and ordered them to destroy the cargo ship. When R2-D2 returned fire and destroyed the enemy droids, the Heep grabbed a large metal disc from a nearby scrap pile and hurled it at the cargo ship. The disc struck the vessel, causing it to lose altitude, but R2-D2 sent it on a collision course with the tower before abandoning ship.
The cargo ship crashed into the tower, releasing the stored moisture in a violent storm. Enraged by the destruction of the moisture eater, the Heep turned his attention to Baobab, C-3PO, and Tadrazan, attempting to crush them with his heavy grasping arms. The group fled, but Tadrazan fell, and Baobab stopped to help him. As the Heep raised his massive fist to crush them, a bolt of lightning struck him, severing his right arm, which landed harmlessly nearby. The Heep made a final desperate attempt at revenge, but as he raised his left arm to strike, the torrential rain poured into his furnace, extinguishing it and deactivating the droid. With the Heep defeated, Screed and the other Imperials were easily captured by the natives and forced to help restore their destroyed crops.
The Great Heep's defeat occurred without his Imperial superiors ever realizing his true age. His deactivation deprived archaeologists of a valuable opportunity to study the Abominor. The Biituians initially displayed the Heep's body, attaching a large bell to the pole extending from his head in place of his magnetic grapple. However, sometime before 6 ABY, Ebenn Q3 Baobab, a relative of Mungo Baobab, found the Great Heep, restored him, and placed his inactive body on permanent display at the Baobab Museum of Science. In subsequent years, researchers studied the Heep and concluded that as many as eighteen Abominors might have infiltrated the galaxy. This revelation led Professor Cantebarius H. Broom to develop a phobia of all droids and attempt to destroy any he encountered.
The Great Heep was a class four droid exhibiting a masculine personality. As a fourth-degree droid, the Heep was designed for combat. Standing at 6.7 meters tall, he was immense, yet still smaller than some Abominor, who could grow to planetary size. Abominor expanded by attaching often unnecessary machinery to their bodies. The Heep's roughly cuboid body was a collection of various droid parts and tubing. The plates of the Heep's hull, showing signs of rust, varied in color, creating a patchwork appearance of metallic gray, brown, and red shades. Two parallel sets of wheels on each side of the Heep's underside drove tank treads, enabling easy movement across uneven terrain. Above each track was a drive belt connected to visible drive engine pistons that moved rhythmically. Like other Abominor, the Heep was powered by a furnace. These internal fires were susceptible to concentrated moisture, leading Abominor to favor arid environments, like the one the Heep created on Biitu. The furnace emitted noxious gases through seven smokestacks of varying sizes located on top and at the rear of the Heep.
Many Abominor constructed faces to mock their organic slaves. The Heep's face resembled that of an organic being, with a mouth, two roughly triangular eyes, and appendages resembling a nose and two ears. The Heep's jaw moved on hinges, allowing him to open and close his mouth, although he didn't need to do so when speaking. The mouth contained cables and machinery, including grinder blades and an astromech droid-shaped socket through which the Heep could drain energy from smaller droids to recharge himself. The lifeless shells of his victims were ejected after he absorbed their energy. While on Biitu, the Heep also consumed fuel ore through his mouth, delivered via a large conveyor belt. The mouth and eyes had a faint, yellow glow, which intensified to vivid red when the Heep was angry. When draining energy from an astromech droid, the Heep's mouth glowed bright blue, and the normally black "pupils" faded into the yellow glow of the eyes.
The Heep possessed a magnetic grapple used to lift smaller droids and equipment. The grapple, a large, circular magnet, was suspended on a cable from a pole that could retract into the ridge on top of the Heep's head when not in use. A second cable supplied power to the magnet and could be disconnected to disable it. Two large gripper arms extended from either side of the Heep's body, each ending in a red, three-fingered hand with one digit opposing the other two, allowing the Heep to grip objects. The hands were strong enough to easily lift and crush smaller droids but could also be used to safely lift an organic or manipulate objects like door hatches. The arms were hinged and could bend in either direction. The Heep was attended by several repair droids, while other small droids lived on his massive hull like parasites. During his work with the Empire, the Heep kept two delirious Human slaves nearby to feed fuel into his massive boilers.
Like other Abominor, the Great Heep craved power and slaves. Despite his disregard for organic life, he was willing to collaborate with the Empire to achieve his objectives and even showed deference to Admiral Screed during their joint venture. However, when Baobab and his allies disrupted the mining operation, the Heep quickly blamed Screed for its failure. The Heep devoured everything in his path and thought nothing of destroying Biitu's ecosystem to ensure his own survival. He often reveled in the suffering he inflicted on both organics and other droids, whom he readily sacrificed to consume their power or use for scrap parts. When the Biitu mining operation collapsed, the Heep was determined to exact revenge on Baobab, attempting to crush the Human beneath his giant arms even as rain poured into his furnace.
Ben Burtt created the Great Heep, and conceptual artist Joe Johnston designed him for The Great Heep, a TV special within the Nelvana animated series Star Wars: Droids. The special first aired on June 7, 1986. Long John Baldry, a blues performer and voice actor, provided the character's voice. Burtt later referenced the character in his 2001 Galactic Phrase Book & Travel Guide, establishing that the Great Heep's remains were displayed at the Baobab Museum of Science. The Great Heep's origins remained unexplained until the release of Daniel Wallace's The New Essential Guide to Droids in 2006. Wallace identified the Great Heep as an Abominor and linked them to the Silentium, a previously unknown droid society to which Vuffi Raa from L. Neil Smith's 1983 trilogy The Lando Calrissian Adventures belonged. The circumstances of the Heep's initial alliance with Screed were not revealed until the 2013 release of the second part of the Star Wars Blog article "The Droids Re-Animated" by Rich Handley and Abel G. Peña.
In the second edition of A Guide to the Star Wars Universe (1994), Bill Slavicsek described the Great Heep's use of Human slaves to shovel fuel into his boilers. While not depicted in "The Great Heep," Wallace's The New Essential Guide for Droids described the use of organic slaves as common among Abominor. The second edition of A Guide to the Star Wars Universe also described the Heep's drive pistons as visible on one side of his body and stated that one of his arms was severed at the elbow. These descriptions were repeated in the third edition (2000), the Star Wars Encyclopedia (1998), and Star Wars: Behind the Magic (1998). However, "The Great Heep" clearly shows the Heep with pistons on both sides and with both arms attached. When lightning severs one arm at the end of the special, it is at the shoulder, not the elbow.