|Specifics: This is for Ghostbusters 101|
Psychomagnotheric Slime (also known as Mood Slime and Psycho-Reactive Slime) is a powerful psycho-reactive substance in Ghostbusters II and Ghostbusters: The Video Game that responds to human emotional states, both positive and negative, from which its reactions depends. It's main characteristic is an ability to open portals for ghosts to enter our realm, and it can also animate objects.
Primary Canon History
The origin of the Mood Slime is tied to a juvenile Sloar, held in Shandor Island, beneath the Hudson River. Before his death, Ivo Shandor and his Cult of Gozer had somehow lured the young Sloar from its home hell dimension and imprisoned it in our world within a Ghostworld pocket at the heart of Shandor's island mansion. Fueled by hatred, bile and anger the creature produced a steady stream of Black Slime.
Ivo Shandor, through experimentation and using equipment decades ahead of it's time, converted the Black Slime into what became known as the Mood Slime,  which was then pumped directly into New York's sewers and abandoned tunnels,  possibly as a means to help Gozer's crossing over. This act was later used by Vigo to his own advantage.
Ray Stantz and Egon Spengler conducted many tests on it to see how it reacts to different behavior. The tests included shouting, and insulting its weak electro-chemical bonds; as well as talking and singing to it, saying supportive nurturing things, and (in Egon's case, to the shock of the others) sleeping with it. Psychomagnotheric slime also has kinetic properties; it can cause a toaster to dance, or a bathtub to eat a baby as seen in Dana's bathroom. The slime also could be used by ghosts to enter the real world or boost their own power.
The slime concentrated in New York beneath the streets was under the control of a powerful spirit, Vigo, who used it to gather more power, form a shell of slime over the museum, and even used the slime to try to abduct Oscar. As the slime was building up in under the city it fed and grew in the old pneumatic transit lines due to the hostility and general negative emotions of the average New Yorker. Direct contact with this slime had the effect of filling a person with the negative emotions that it stores. Slime can also be positively charged. In this state, it can be used to move large monuments, small toasters, or even rid someone of a possession. The Ghostbusters used it in their Slime Blowers to animate the Statue of Liberty. Under Vigo's influence, negatively charged slime could even become aggressive enough to attack a person (as seen in a scene where Ray takes samples of it).
Ghostbusters: The Video Game
By 1991, Egon has further refined the substance into a more useful tool. Using his knowledge of spores, molds and fungus, Egon had developed an energetic, self replicating growth medium that can in theory provide an endless supply of positively charged slime and allowed for the Mark II Slime Blower to consist of only a small reservoir that can be attached to the standard Proton Pack. This is referred to as the Plasm Distribution System.
The primary reason for developing this medium is as a counter agent for the caustic Black Slime, a super-saturated negatively charged form of Ectoplasm that can create portals across the 4th and 5th dimensions into the Ghostworld. As a side effect, the pigment of the slime has changed from it's original pink into a dark green and although most of it's "emotive", "portal-opening" and "animating" properties have been reduced, care still needs to be taken while using the slime around loud punk, heavy metal and hip-hop music.
According to Tobin's Spirit Guide
- Category: None
- Abilities: Melee Attack, Black Slime Spit, Black Slime Coating
The standard response by most people to paranormal entities is often fright. I've seen some reactions to ectoplasm that run counter to this standard expectation. Some people, in fact, react angrily or become elated while others grow morose. I've isolated such incidents and can conclude that the ectoplasm residue in these cases is a subclass that seems to resonate and reciprocate human emotions.
Mood slime. With our recent breakthroughs in psychomagnatheric ectoplasm technology, we can align the valences of the substance to elicit a finely tuned range of emotions upon contact with a human target.
Don't get it on you...unless you're in a good mood.
The art page can be found in Shandor's Island, during the "Through the Good Slimes..." section. It is hidden inside a locker in the room Peter is being held in.
- Comes in various hues from blue, green, yellow, and pink. While it is usually pink, the Ghostbusters managed to re-work it into more useful, but less powerful, positively-charged version, which is green.
- Could be charged by positive or negative energy, which drastically changes its behavior.
- Able to animate inanimate objects, like toasters, fur coats and even the Statue of Liberty. These objects could behave either hostile or benign, depending on the charge.
- Negatively charged mood slime can be used to create rifts for ghosts to cross dimensions or to boost and extend their own power or even as a weapon itself, as demonstrated by Vigo.
- In Ghostbusters II, when Egon Spengler and Ray Stanz scanned 1st Avenue where Dana Barrett's carriage was taken by the pink slime, it registered 1,118 on the P.K.E. Meter and 2.5 GeV on the Geiger Meter.
- In its positive state, mood slime can drive out a possession as well as greatly weaken or even harm a powerful entity.
Psychomagnotheric Slime was used as a means to stop negatively charged objects, people, and ghosts as it neutralizes the negative energy and makes whatever it gets on to be inert. It was used in the Slime Blower in Ghostbusters II and in the updated Proton Pack in both versions of Ghostbusters: The Video Game.
Secondary Canon History
The Real Ghostbusters
After the battle with Vigo the Carpathian, the Ghostbusters collected the Psycho-Reactive slime.   Experiments proved it responded to a person's thoughts and emotions.  It could also grant a person limited ghostly powers such as flight.   Egon never could understand how it worked completely, though.
The next year, the Ghostbusters utilized the last of the slime in order to rescue Janine Melnitz and Louis Tully on Janine's birthday from Poso. They recruited Poso's former associate Shifter to aid them. However, Shifter stated he could only smuggle one of the Ghostbusters into Ghost Town, Poso's base of operations. Peter Venkman was volunteered and covered in the slime, currently in a yellow hue. After the rescue mission was a success, it became apparent the slime grew fond of Peter.  When Peter lost his temper, the slime changed its hue to red and skipped away with him in tow. They didn't get it off until Peter calmed down. 
During the Ghostbusters' trial in 1989, a Officer Mallory decided to keep some of the confiscated Psychomagnotheric Slime for himself as a way to save money on ooze refills for his son's pirate reptile toys. Winston Zeddemore noticed him and his partner looking at the slime outside the court room. Winston tried to warn them the slime was dangerous but they snapped at him. The slime and negative emotions gave way to the manifestation of Mama Scoleri. Winston went outside to Ecto-1, found a Trap, and captured her.
For a trip across the United States of America, the Ghostbusters took along several equipment including Slime Blowers. While in New Orleans, Peter doused an angry mob in positively charged pink slime so the Ghostbusters could move onto meet with their client. Peter later used a Slime Blower set on Slime Tether mode to neutralize the Phantom Big Rig.
A year later, Egon attempted to neutralize Yellow Slime covering Janine Melnitz but the positively charged pink slime dissolved on contact and had no effect whosoever. During Halloween blasted a section of the Ghost Fire Wall around Central Park with positively charged pink slime. The slime successfully dissipated enough of the wall for the Ghostbusters to venture forward into the park. Ray was later tasked with dissipating the rest of the wall. The positively charged pink slime was also used for a Miniature Slime Blower Egon used against a projection of Santa Muerte.
After Tiamat trapped Dana in her apartment, she observed one of the brick wall obstructions seething with Psychomagnotheric Slime. Dana refused to wilt and kicked the brick wall away and tried to escape. The positively charged slime proved effective on liberating the Hart Island Ghosts from Vigo's control. After Winston Zeddemore sprayed them, they immediately swarmed Vigo. During an investigation at the St. Augustine Lighthouse on August 29, a liter of positively-charged Psychomagnotheric slime was brought along. The Ghostbusters later discovered a cursed statue at the nearby St. Augustine Alligator Farm Zoological Park. After the statue was neutralized in positively-charged Psychomagnotheric Slime, they were able to trap the Ghost Alligators. P.K.E. levels stabilized and the benign resident ghosts returned to their standard manifestations. On September 14, the Ghostbusters used negatively charged Psychomagnotheric Slime on Hedylogos. Hedylogos suffered visible pain, which disrupted its influence and weakened its P.K.E. reading significantly, which allowed them to trap it.
Michelangelo was curious about the Miniature Slime Blower so Peter explained it was concentrated good vibes to counter the negative energy of a direct possession.  Michelangelo was able to weaken Chi-You's possession of Winston with a stream of slime from a Slime Blower. Leonardo then zapped Winston with a modified Arm Mounted Proton Pack and fully exorcised Chi-You.
An even more compact mobile device was invented, the Slime Spritzer. They were utilized in the Louvre Museum. However, after the slime made contact with the Animated Louvre Art, the David, the Venus de Milo, the Mona Lisa and the Code of Hammurabi, the priceless works of art disintegrated. After the Ghostbusters secured the Rauoskinna, Peter sprayed positively charged Psychomagnotheric Slime on the cover in order to sever its connection with the ghost of Gottskalk Nikulausson. The use of positively charged Psychomagnotheric Slime in a highly negative environment has a caustic effect on corporeal entities. Ray was able to verify this by using his Slime Blower while the Ghostbusters were stuck in Hell. He slimed several of Hell's Demons. They screeched in pain as the slime melted parts of skin off their wings and bodies.
- There are three spellings of this type of ectoplasm.
- The subtitles for Ghostbusters II, included in the Double Feature Gift Set, spell it as "Psychomagnotheric."
- A February 27, 1989 script draft of Ghostbusters II from Spook Central spells it as "Psychomagnetheric" on Page 86.
- The Tobin's Spirit Guide entry in Ghostbusters: The Video Game (Stylized Version) spells it as "Psychomagnatheric."
- Harold Ramis' original concept of the slime was "bad vibes could collect under large population centers and New York was experiencing this kind of seismic level of paranormal activity because the city was about to blow" and his idea was "the people of New York had to be nice to each other because the city could not stand anymore bad vibes." Ramis admitted he had several ways to dramatize the latter. 
- In the Ghostbusters II August 5, 1988 draft, the term "psychmagnetic" precedes "psychomagnotheric" and it is explained it represents a new energy composed of P.K.E. antiparticles.   
- In the Ghostbusters II August 5, 1988 draft, several songs are studied find something to combat the negative forces - "Cumbaya," "All You Need Is Love," "Give Peace a Chance," "It's a Small World," - but they choose the 1970 Ray Stevens hit, "Everything is Beautiful" as the primary song to use. 
- The negative emotions materializing as slime was a late addition to the movie. 
- The slime appears on the Second Printing cover of Ghostbusters Issue #2.
- The slime appears on Cover B of Ghostbusters Issue #9 in the background.
- On page 19 of Ghostbusters Issue #14, a bucket of Psychomagnotheric Slime is near the board.
- On page 3 of Ghostbusters Issue #16, a jar of Psychomagnotheric Slime, like it was stored in Ghostbusters II, is on the table near the Christmas Tree. Later in the issue, it is spilled over.
- On the Ghostbusters: Get Real Issue #2 Regular Cover, Ray is holding a jar of Psychomagnotheric Slime as seen in Ghostbusters II.
- In Ghostbusters International #2, Special Agent Melanie Ortiz' spectral incident report mentions the use of negatively charged Psychomagnotheric Slime - a first in the comics.
- On page 13 of Ghostbusters International #5, Ray mentions the Mood slime is self-replicating. This was first brought up in Ghostbusters: The Video Game, Realistic Versions when Egon and Ray teach Rookie about the Plasm Distribution System.
- Vigo - The ghost that used Mood Slime as his main source of power.
- Sloar - The creature that produced Black Slime, from which the Mood Slime was derived.
- Black Slime - The original ectoplasmic slime from which the Mood Slime was created.
- Ethan Kaine - A ghost who also used Mood Slime as a source of power
- Ongoing Series
- Volume 1
- Volume 2
- Teenage Mutant Ninja Turtles Ghostbusters
- Ghostbusters Get Real
- Volume 3
- Ghostbusters International #1
- Haunted America Case File only
- Ghostbusters International #2
- Haunted America Case File only
- Ghostbusters International #5
- Ghostbusters International #6
- Mentioned in What Came Before Page! 
- Ghostbusters International #7
- Haunted America Case File only
- Ghostbusters International #9
- Ghostbusters International #10
- Ghostbusters International #11
- Ghostbusters International #1
- Ghostbusters Annual 2017
- Where Winston Was
- ↑ GBTVGReferenceMoodSlimeRV02.jpg
- ↑ GBTVGReferenceMoodSlimeRV01.jpg
- ↑ Egon Spengler (2009).The Real Ghostbusters- "Partners in Slime " (1989) (DVD ts. 10:32-10:38, 10:42-10:45, 10:49-10:54). Time Life Entertainment. Egon says: "I collected it last year after we battled Vigo the Carpathian."
- ↑ Egon Spengler (2009). The Real Ghostbusters - "Partners in Slime" (1989) (DVD ts. 10:39-10:40). Time Life Entertainment. Egon says: "It's Psycho-Reactive Slime."
- ↑ Ray Stantz (2009). The Real Ghostbusters - "Partners in Slime" (1989) (DVD ts. 10:40-10:42). Time Life Entertainment. Ray says: "It responds to your thoughts and emotions."
- ↑ Egon Spengler (2009). The Real Ghostbusters - "Partners in Slime" (1989) (DVD ts. 10:43-10:48). Time Life Entertainment. Egon says: "It should give you limited ghostly powers and help you pass off as the real thing."
- ↑ Egon Spengler (2009). The Real Ghostbusters - "Partners in Slime" (1989) (DVD ts. 10:51-10:53). Time Life Entertainment. Egon says: "It can even fly."
- ↑ Egon Spengler (2009). The Real Ghostbusters - "Partners in Slime" (1989) (DVD ts. 24:17-24:21). Time Life Entertainment. Egon says: "Being Psycho-Reactive, the slime has apparently grown quite fond of you."
- ↑ Egon Spengler (2009). The Real Ghostbusters - "Partners in Slime" (1989) (DVD ts. 24:57-25:00). Time Life Entertainment. Egon says: "Unfortunately not until Peter does."
- ↑ Peter Venkman (2015). IDW Comics- "Teenage Mutant Ninja Turtles/Ghostbusters Issue #4" (2015) (Comic p.16). Peter says: "That was Mood Slime. Concentrated good vibes. We use it to counter the negative energy of a direct possession."
- ↑ MoreWhatnot.com Lost Harold Ramis Interview 1/27/12
- ↑ Aykroyd, Dan & Ramis, Harold (1988). Ghostbusters II (August 5, 1988 Draft) (Script p. 18). "Egon Spengler says: "Ray and I have been working on a radical new theory. We know that PKE, psychokinetic energy, is the unifying force on the so-called etheric plane."
- ↑ Aykroyd, Dan & Ramis, Harold (1988). Ghostbusters II (August 5, 1988 Draft) (Script p. 19). "Egon Spengler says: "Even though we traditionally think of energy traveling in waves, we know from quantum mechanics that energy is actually composed of particles' and we also know that every particle has an antiparticle."
- ↑ Aykroyd, Dan & Ramis, Harold (1988). Ghostbusters II (August 5, 1988 Draft) (Script p. 19). "Egon Spengler says: "We've discovered a new energy composed of PKE antiparticles. I call it the "psychomagnetic force" and I've been able to detect it everywhere I've looked."
- ↑ Aykroyd, Dan & Ramis, Harold (1988). Ghostbusters II (August 5, 1988 Draft) (Script p. 87). Ray Stantz says: "My colleagues and I identified several songs that seem to have a calming or mediating effect on intense human emotions. We studied "Cumbaya," "All You Need Is Love," "Give Peace a Chance," and "It's a Small World" but based on the results of our last computer run we selected the 1970 Ray Stevens hit, "Everything is Beautiful.""
- ↑ MoreWhatnot.com Lost Harold Ramis Interview 1/27/12
- ↑ Kylie Griffin (2014). IDW Comics- "Ghostbusters Volume 2 Issue #14" (2014) (Comic p.11). Kylie says: "The last time she saw Dr. Venkman, there was a powerful psychoemotional discharge involved. You know - the Pink Slime?"
- ↑ What Came Before! Page (2016). IDW Comics- "Ghostbusters International #6" (2016) (Comic What Came Before! page). Narrator says: "Still, they sprayed mood slime on some of the most priceless artwork known to man. That stains, y'know."