The Collectors, when summoned properly, can make people disappear. The summoning ritual itself will drive the spell caster insane. They were known to be involved with an incident in Jamestown and the disappearances of John Cabot in 1499, Amelia Earhart on July 2, 1937, Agatha Christie in December 1926, Camilo Cienfuegos on October 28, 1959, D.B. Cooper on November 24, 1971, and Jimmy Hoffa on July 30, 1975.  In December, before Christmas, Idulnas forced Janosz Poha into letting him take possession. Idulnas painted the summoning spell on the wall of Janosz' room at Parkview Psychiatric Hospital with the names of the four Ghostbusters.
In February, the Collectors teleported to the physical plane and split up to capture each of the Ghostbusters. Peter Venkman was the first taken while he was walking to the Ritz Cafe with Special Agent Melanie Ortiz. The demon simply stated he 'had come for Peter' and refused to come at a later time. It shot its thrower and wrangled Peter. The demon then pulled Peter into his chest cavity and the two vanished. At the same time across Manhattan, the other Ghostbusters were taken in similar fashion. Egon Spengler was taken from the second floor of the Firehouse, Ray Stantz was taken while out on a bust, and Winston Zeddemore was taken from his apartment. Janine Melnitz formed a new team and try and find the Ghostbusters but made no progress after three months. The Ghostbusters, meanwhile, were stranded in an interdimensional limbo by their captors.
The Ghostbusters were the first to escape their custody and return home. The summoning spell began to react violently. The power went out in the Parkview Psychiatric Hospital, the P.K.E. levels spiked, and the painting itself changed colors constantly. The Collectors arrived at the hospital and began to hunt down the Ghostbusters. The one that resembled Egon disguised itself as a wheelchair-bound patient and approached the Ghostbusters in the lobby while the one resembling Winston tried to grab Winston from behind. Melanie saw him at the last minute and blasted at him. Both Collectors teleported away. Egon decided the best plan was to split up in teams to also separate the Collectors and see if they could be trapped. Melanie and Winston were about to jam a Trap in a Collector's chest and capture him but it became apparent he would not be held long.
Idulnas tired and exploited a loophole in the summoning ritual. Since Janosz was the summoner, Idulnas was free to control and manipulate the Collectors. Kylie attempted to drive a wedge between Idulnas and Janosz. Janosz refused to be the patsy of another supernatural being and altered the summoning spell by painting Idulnas' name on the wall. The Collectors' appearance changed and they teleported straight to Janosz' room. One violently extracted Idulnas from Janosz' body and they returned to their plane of existence. The Ghostbusters didn't want to be taken by surprise again and began to research extradimensional theory. Egon consulted with a witch doctor on Bleecker about barring the Collectors from the physical plane of existence.
In a ghostly limbo, Darius Dun continued to be consumed with rage over his death at the hands of Splinter and the Foot Clan and desired revenge. Bronson, a fellow ghost, hinted he heard about the Collectors, beings who exist only to hunt and capture. Darius immediately wanted to know how to contact them. Bronson tried to warn him there was an awful cost, even for ghosts, but Darius didn't care.  Darius summoned the Collectors and marked the Teenage Mutant Ninja Turtles, Splinter's sons, for capture. The Turtles were just about to leave Dimension X then the Collectors appeared. At first, they mistook the Collectors for natives of Dimension X until they took on grotesque forms of the Turtles and attacked. The Turtles soon realized they couldn't make physical contact with them. Using his quick thinking and eidetic memory, Donatello reset the transporter's controls to the coordinates of the Ghostbusters' dimension and jumped through the portal.
Donatello successfully crossed over, landed on the second floor of the Firehouse, and quickly told Egon and Ray what happened. The Collectors arrived for Donatello. Egon reminded Ray their last encounter ended without a final resolution. Ray fired a Particle Thrower at them to no avail. They remembered the Ghostbusters and warned them to stay out of their hunt or they would turn their attention back to them. Egon recovered trace ectoplasm left behind and secured a way to discern the dimensional frequency of their prison dimension. The Ghostbusters held a meeting to figure out what to do next. Peter blamed all of it on Ray for wishing for more adventures earlier in the day. Ray revealed he had an idea on how to permanently contain the Collectors. Over the next three weeks, roughly, Egon and Ray invented Remote Portal Access Bands and Experimental Mental Communications Devices. Peter, Ray, and Winston went through a portal generated by the Interspatial Teleportation Unit to the Collectors' Limbo and found the Turtles. Winston wore one of the Mental Communication Devices while Ray gave the other to Donatello to wear and told him to go through the portal only. The Collectors would read Winston as Donatello and vice-versa temporarily. To further slow them down and buy time for Egon and Donatello, the other Ghostbusters and Turtles paired up and used the Remote Portal Access Bands to make a series of random jumps to various dimensions. This would also exploit the Collectors' weakness of working together as a single unit. With them paired off on three tracks, the Collectors would have a harder time tracking them than if they jumped all together. Egon revealed to Donatello he needed his knowledge of transdimensional mechanics to capture the Collectors once and for all. Egon directed Donatello to a simulation he was running to determine how long the others could successfully evade the Collectors. They had less than a day's time.
Egon admitted Donatello's familiarity with the unmodified portal technology was key and the notes he left behind were lost. The computer revised its calculations with further data from the dimensional breach alarm and predicted the Collectors would take even less time to find and capture the Turtles. Egon fully revealed his idea was to combine the portal technology and Traps into a Trap-Gate that would send the Collectors directly into the Containment Unit. Dontallo inquired if he had any ideas on how to make sure they didn't escape before they were trapped. Egon had none at the moment. Donatello made a call then they returned to their new invention. Donatello believed they just had to boost the Trap-Gate's power by a factor of three but he was suddenly electrocuted by the Communications Device and suffered neural confusion with Winston. It suddenly felt like his brain was everywhere at once and he could feel the Collectors searching for the Turtles. Donatello felt a renewed sense of urgency and revealed his plan to keep the Collectors at bay was to create proton-powered versions of the Turtles' weapons. Winston recovered his access band after it was stolen by The Frogs. Before he could open a breach to the next dimension, the Collectors arrived.
Winston fired his Proton Pistol at maximum power then told Leonardo to use his thrower. They failed to atomize the Collectors. Winston started to think they should surrender and wait for a chance to escape the Collectors' Limbo. Luckily, they were summoned away by Darius for an inquiry. He demanded an explanation for their failure. Bronson was alarmed by his rash choice. The Collectors were angered he cost them the chance to capture Leonardo. Bronson tried to step in and cover for Darius, claiming he meant no offense. He wasn't having it and shoved Bronson aside for presuming to speak for him. He stated he expected results from those he hired. They found Darius mad to summon them again and decided to take the entirety of his being than a piece of his soul. They were poisoned by the growing madness in his essence and were completely taken over by Darius. Bronson was horrified at what he caused for trying to be a friend. Darius didn't feel the same way. He felt "reborn" with his mind completely restored and possessed all of the Collectors' knowledge and power. He realized they was no longer bound by their rules and could travel wherever he pleased. He decided to collect the heads of the Turtles then kill Splinter.
Darius sensed the Turtles in the Ghostbusters' dimension and teleported to Central Park. Peter addressed them and played his part in stalling them until the Turtles got into position and attacked. Peter offered him the chance to surrender. Darius was amused but realized there was a condition in place that required him to deal with the Turtles first before he was completely free to do whatever he wanted. Darius revealed he planned on killing the Ghostbusters and Turtles then he would build an eternal criminal empire across the multiverse. Peter found him "full-tilt bugnuts." Leonardo sliced the green Collector in half at the torso with his Proton Swords. They were surprised to feel pain but vowed to destroy them. The Turtles and Darius fought. They failed to notice Ray and Egon fine-tune the Trap-Gate to their unique P.K.E. signature. Peter and Winston came to the Turtles' aid and opened fire. Darius recalled the Collectors could not be contained by the Ghostbusters and underestimated the Trap-Gate. All four were drawn through its portal into the Containment Unit. The capture of the Collectors caught the attention of many, including Tiamat, and sowed panic across the multiverse. She took a renewed interest in the Ghostbusters and realized they had the potential to spread chaos faster than any of her servants ever did.
Based on the appearance of the Collector who took Peter, the Collectors base their physical traits on the Ghostbuster they were tasked with capturing. Their peculiar affectation is to take on the aspects of their prey's appearance - filtered through their own grotesque sensibilities - before the abduction.
Tobin's Spirit Guide
In Tobin's Spirit Guide, the Collector's entry is in Greek and refers to a place called Abbadon, the realm of the dead, in reference to their interdimensional limbo.
The Collectors can teleport at will from their limbo to the physical plane and vice-versa, take human victims with them by stuffing them into their chest cavity, shapeshift, and extract a possessing entity from a host. The Collector that took Peter was able to fire an ectoplasmic version of the Proton Stream to wrangle his prey. The Collector that took Egon, when controlled by Idulnas, fired a P.K.E. blast. The Collectors are also too powerful to be permanently held in a Trap. The Collectors have one weakness. They share a hive mind and work together as a single unit.   If all four are placed inside the Containment Unit at the same time, they can't escape it. 
- The Collectors are loosely visually based on the Peoplebusters from The Real Ghostbusters episode "Flip Side"
- The name patches on the Collectors' jumpsuits are from the 2009 edition of Dan Schoening's 13 Days of Halloween drawings.
- In some panels of Ghostbusters Volume 2 Issue #4, the patches are purposefully misspelled in homage to common misspellings over the decades for Zeddemore and Stantz.
- On the Ghostbusters: Mass Hysteria back cover, the Collectors are alluded to in the description.
- On Cover A of Teenage Mutant Ninja Turtles/Ghostbusters Volume 2 Issue #1, and the rest of the series, the Collectors' new forms are visually based on the Dark Turtles from the "Teenage Mutant Ninja Turtles Fast Forward" animated series.
- On page 5 of Teenage Mutant Ninja Turtles/Ghostbusters Volume 2 Issue #4, the Collectors' price for being summoning by a ghost is revealed to also be a piece of their soul.
- IDW Comics
- Ongoing Series
- Teenage Mutant Ninja Turtles Ghostbusters
- Ghostbusters: Get Real
- Teenage Mutant Ninja Turtles/Ghostbusters Volume 2
- Ghostbusters Annual 2018
- Mentioned on the What Came Before page. 
- Ghostbusters Crossing Over
- Insight Editions
- Tobin's Spirit Guide
- Section III: Metaspecters
- Pages 46-47
- Section III: Metaspecters
- Tobin's Spirit Guide
- Cryptozoic Entertainment
- Narrator (2013). IDW Comics- "Ghostbusters Volume 2 Issue #4" (2013) (Comic p.1). Narrator says: "The Collectors are demons that can whisk away anyone for the low, low price of your soul and sanity."
- The Collectors (2017). IDW Comics- "Teenage Mutant Ninja Turtles/Ghostbusters Volume 2 Issue #4" (2017) (Comic p.5). The Collectors say: "Our price is a piece of the soul. The loss causes madness."
- Kylie Griffin (2013). IDW Comics- "Ghostbusters Volume 2 Issue #2" (2013) (Comic p.3). Kylie says: "I'd say these guys are our prime suspects. When they're summoned properly, they make people disappear. Jamestown. Amelia Earhart. D.B. Cooper. You just need to be crazy to summon them. Literally, because the ritual itself can drive you insane."
- Bronson (2017). IDW Comics- "Teenage Mutant Ninja Turtles/Ghostbusters Volume 2 Issue #1" (2017) (Comic p.6). Bronson says: "There's an awful cost to summoning them, even for ghosts."
- Tiamat (2018). IDW Comics- "Ghostbusters Crossing Over Issue #8" (2018) (Comic p.3). Tiamat says: "And to top it all off... you actually captured the Collectors. Such powerful beings being undone and imprisoned by mortals -- this sent ripples across the multiverse. It sowed panic like you couldn't believe. And panic... gives birth... to chaos."
- Narrator (2016). Insight Editions- "Tobin's Spirit Guide" (2016) (Book p.46). Paragraph reads: "CLASS VI. TRANSDIMENSIONAL."
- Dramatis Personae (2017). IDW Comics- "Teenage Mutant Ninja Turtles/Ghostbusters Volume 2 Issue #1" (2017) (Comic Dramatis Personae). Dramatis Personae reads: "Relentless demons who are summoned to share after and capture the living, they share a hive mind, and can cross dimensions at will."
- Egon Spengler (2017). IDW Comics- "Teenage Mutant Ninja Turtles/Ghostbusters Volume 2 Issue #1" (2017) (Comic p.19). Egon Spengler says: "You see, while it's true the Collectors can easily travel to any dimension, they do have a weakness -- they work as a single unit."
- Egon Spengler (2017). IDW Comics- "Teenage Mutant Ninja Turtles/Ghostbusters Volume 2 Issue #4" (2017) (Comic p.17). Egon Spengler says: "If even one of the Collectors is left free, the others will be able to escape the Containment Unit."
- Kylie Griffin (2014). IDW Comics- "Teenage Mutant Ninja Turtles/Ghostbusters Issue #1" (2014) (Comic p.13). Kylie says: "He means gods or demons making a big entrance, like the Collectors or Gozer."
- Peter Venkman (2015). IDW Comics- "Ghostbusters: Get Real Issue #1" (2015) (Comic p.18). Peter says: "We got stuck in a limbo once by some demons with a bit of a grudge."
- What Came Before page (2018). IDW Comics- "Ghostbusters Annual 2018" (2018) (Comic What Came Before page). Narrator says: "They've rescued their mutant friends from the tyranny of the demonic COLLECTORS and put a stop to that threat for good."
- New Ghostbusters Biography (2018). IDW Comics- "Ghostbusters Crossing Over Issue #3" (2018) (Comic Dramatis Personae p.1). Line reads: "An FBI agent, a researcher, and administrative head of the Ghostbusters, who first banded together when the Prime Ghostbusters were kidnapped by a demonic force."
- Egon Spengler (2018). IDW Comics- "Ghostbusters Crossing Over Issue #4" (2018) (Comic p.4). Egon Spengler says: "It was something we used to help some friends escape capture by a set of very persistent demons."
- Koza'Rai (2018). IDW Comics- "Ghostbusters Crossing Over Issue #5" (2018) (Comic p.16). Koza'Rai says: "They have actually captured the Collectors!"
- Tiamat (2018). IDW Comics- "Ghostbusters Crossing Over Issue #5" (2018) (Comic p.17). Tiamat says: "-- It was, in fact, their capture of the Collectors that caught my attention."
- Narrator (2015). Cryptozoic Entertainment- "Ghostbusters: The Board Game" (2015) (Comic p.4). Narrator says: "Most recently, he was pulled into a limbo by a band of demons that he had intended to set on the Ghostbusters."