Dr. Egon Spengler was one of the original Ghostbusters and was known as the brains of the outfit. He appears in all three animated series which are The Real Ghostbusters, Slimer!, and Extreme Ghostbusters. The Ghostbuster that most commonly wore a blue uniform with pink trim. However, due to low color pallets he sometimes wore green or cyan uniform in the comics and promotion items.
As he is in the movies, animated Egon is the brains of the Ghostbusters. He many times will save the day by coming up with ways to defeat the ghost with a different setting on the equipment. He keeps to himself mostly. A traumatic experience with the Boogieman as a child served as the impetus for him getting involved in researching the paranormal and finding ways to combat it. Blushing, he confessed once that his mother, nicknamed him "Spookums."
Egon has on occasion displayed a dry sense of humor. He also has little patience for non-scientific ways of approaching matters and frivolity in general. One of the few times he ever showed genuine terror was shortly after a near-death experience by getting knocked off the World Trade Center, saved only by Winston's masterful control of Ecto-2. When believing that his death was imminent in a ploy to stop Ragnarok from occurring, he uttered Janine's name with a slight tone of sorrow and regret.
Compared to his live action incarnation, RGB Egon is less prone to emotional outbursts and less likely to make a wisecrack. But both are fairly equal in obsessive interests in science and lack of social skills.
Changes Over the Seasons
His appearance changes slightly from RGB to EGB. He changed his hairstyle at some point between Real Ghostbuster to Extreme Ghostbusters from his trademark pompadour and rat tail to a simple pulled back ponytail. His glasses change from rounded frames to more oval shaped.
Egon still wears a variant of his grey RGB coveralls in EGB, this time without the magenta cuffs and collar. In the EGB toyline he's been shown to wear both blue and green colored jumpsuits.
Characteristically he's the same phlegmatic type from RGB. He does seem to have accepted Janine as a regular part of his life, as he's been shown on one occasion holding her and even kissing on another, although that was initiated by Janine.
Egon after being alone for years maintaining the Firehouse along with keeping Slimer there. However, the P.K.E. Meter started going off in the Firehouse, Slimer took it to Egon who was at the University teaching students. Egon after getting the meter, went to the site of activity and no one believed him about the tunnel.
After tons of calls Egon decided it would be best to reopen the Ghostbusters. His role was of a mentor for the new team of Ghostbusters. For the most part, he usually leaves the field work to the new members, opting to provide audio back-up from the firehouse and information on their current adversary. He would still take to the field on some missions, but express frustration that he was no longer as agile or quick as when he was younger, and being very conscious of his age (39), in "The Sphinx."
Relationship to Others
As Ray is the other technical genius on the team, Egon and Ray frequently create and test out new equipment, as well as discuss paranormal theories origins of ghosts and solutions on how to capture non-standard entities.
"You know, we're all descendants from fish. It would be no trouble at all to flip back in time, find the fish you descended from, and stuff it into a Cuisinart." -Egon to Peter
Egon is usually indifferent to Peter's sarcasm, and is quick to point out flaws in his logic. At times Egon will display mild exasperation at Peter's lack of professionalism when it comes to the field of science, or when Peter gets distracted a pretty woman. While Peter commonly makes light of Egon's more elaborate scientific terms and social awkwardness, Egon does like him, and the two maintain a solid working relationship despite their differences in personality and scientific approach.
Winston will generally defer to Egon for solutions to capturing more difficult ghosts, and provides support when enacting plans. Winston normally breaks down Egon's complex technical jargon into more "everyman" terms for the rest of the team.
Egon and Janine seem to have always been close to something more than just business. In the Ghostbusters movie there was a few moments that suggested that they may love each other. During most of The Real Ghostbusters the hints were still being thrown around in little parts in the episodes. However, the episode "Janine, You've Changed" finally gave long time fans a bit of payoff, when Egon confessed that he loved her and cared about her. In the NOW comic he admits he has extreme difficulty in articulating his feelings to those he cares about to her.
In Extreme Ghostbusters, the relationship feels much like in The Real Ghostbusters. However, she feels even more like a wife or girlfriend as she cooks for him, always caring for him. When Janine gets kidnapped by the insectoid demon Gregor Samsa (also known as Cohila) to mutate and serve as his queen, Egon displays a notable level of ire in his voice by saying "This time, it's personal!" He helps her regain her human feelings by telling her he loved her. (In an awkward manner)
The two men rarely spoke maintained long conversations with each other. Having never argued or done much together may suggest that the animated series to avoid the Ghostbusters II issue of Janine and Louis relationship. In the comic based on the cartoon from , Egon DID make a barbed comment to Janine about her having more time to spend with Louis when he was about to leave town on a mission, indicating that he noticed it and was bothered by it on some level. Janine immediately told him that Louis was sweet, but harmless, showing her heart was still with Egon. Otherwise, Egon and Louis in their limited exchanges seem to get along just fine, which would imply Egon is not one to hold a grudge.
No matter when in the show, Egon has always got along surprisingly good with Slimer. Many times Egon used Slimer to test new theories and gadgets. Egon in many ways treated him like a pet, and that was still the case during Extreme Ghostbusters.
Most of the time, Egon gets along with Eduardo, however there have been those days that Egon has raised his voice to him in exasperation.
Of the four XGBs, Roland is the one most like Egon and seems to regard him as more of a mentor than Eduardo and Garrett. Both share the same hardcore interest in the more scientific aspects of Ghostbusting.
Garrett relies on Egon's "experience, knowledge and wisdom." He feels that Egon is a leader in every seance of the word.
Egon feels that Kylie is a true paranormal expert. They often talk to one another on the subject. They are on very good terms with one another as Egon serves as her mentor.
She is a very motherly person, as she also treats the other Ghostbusters like her children as well. Janine and her seem to get along pretty good as well. When Egon was a baby, his mother used to call him "Spookums". Egon seems to have inherited his penchant for occasional dry humor and looks from her. She talks by phone with him at least once every six months.
- In addition to a hardback version, Egon owns a paperback copy of "Tobin's Spirit Guide" which he is shown to bring with him on many assignments. By "Extreme Ghostbusters," Egon had also written his own book: Spengler's Spirit Guide and had transcribed it onto CD Rom.
- Egon asserts scientists and scholars are said to run in his family, not Ghostbusters.  However, another ancestor named Eli Spengler later proved to be such. There has also been a wizard, but he is generally never talked about and looked down upon as a crackpot. All his ancestors are shown to resemble him facially, have blond hair and glasses. Curiously enough, Egon's ancestor Eli during the Salem witch trials is also shown to have Egon's pompadour and rat tail hairstyle. All of Egon's shown relatives wear glasses.
- It is also a tradition among Spengler males to repress their emotions and focus on everything in a detachment, scientific manner. This explains why he tends not to be reciprocal to Janine's affections for the most part. But he HAS shown signs that she has taken some claim to his heart. Faint displays of jealousy, disappointment, relief, remorse and even mild pleasure have been displayed by him in matters regarding her. He even admits to her in the comic that he isn't very good at dealing with people he cares about. Egon even said words to the effect that he would not be adverse to the idea of a kiss from her when he got back. He even willingly had dinner with her family
- Egon knows at least four other languages, Sumerian, Sign Language, Russian, and Japanese.
- When Egon was a baby, his mother used to call him "Spookums".  His mother makes a couple appearances on the show. Egon seems to have inherited his penchant for occasional dry humor from her.
- While it isn't outright stated, it seems likely that Egon has a Jewish family background, although he isn't particularly devout regarding it. His name is a Jewish last name and even his mother even shows elements of a stereotypical Jewish mother.
- Egon almost always wears an old-fashioned nightshirt and cap when sleeping. On one occasion he was seen brushing his teeth wearing normal pajamas with molecule chains printed on it.
- Egon's voice changes throughout the season going from deep pitch to match Harold Ramis's voice then changing to higher pitching tone. Until Extreme Ghostbusters sounding slightly more like his early season voice.
- Egon can communicate in Troll language with a Tobin's Spirit Guide present. 
- Egon revealed he met the Boogieman when he was a child. The Boogieman was the reason he started investigating the supernatural, in order to find a way to stop him. 
- Egon knows sign language. 
- Egon has an uncle named Dr. Cyrus Spengler who lives in the Midwest and is employed at Spengler Laboratories. 
- Egon revealed he knew a guy at the University who did a study on the dynamics of the curve ball. 
- Egon's favorite soup is chicken soup with mushrooms. 
- Egon's favorite color is pea soup green. 
- Egon named his one of his computers "Marsha."  
- Egon played with a chemistry set during his childhood. 
- Egon always wanted to be on the cover of a Spooks Illustrated issue. 
- Egon mentioned his home once. 
- Egon Spengler reveals he got a college degree when he was in grade school.  
- It's also been inferred that he originally met Ray and Peter in college as an instructor. 
- As a child, Egon had the largest ant farm in the state of Ohio. 
- Winston revealed Egon once insulted Janine and she quit. 
- Egon considers filing fungus samples a vacation. 
- Egon confesses he once got an A- in college and his parents wouldn't talk to him for a week. 
- This implied his parents were really staunch perfectionists. The only other thing known about Egon's father is that he has a brother, Cyrus.
- The Werechicken egg is the second largest egg Egon has seen. 
- Egon got a microscope for his third birthday. 
- In "The Haunting of Heck House," Egon shows a strong dislike of Book Bats and other such phenomena due to the incident in the New York City Public Library during their first case. Before the ghosts of Heck House barely levitate a book off of a shelf, Egon harshly scolded them and the book quickly slid back into its place on the shelf. 
- When the concept of Extreme Ghostbusters was still in its formative stage, Fil Barlow's initial design of Egon had him as an ambassador to the ghost realm who was trying to stop an impending war on the other side demons and ghosts (but hell was considered a bad idea for a children's show and was changed to a war between ghosts and ghouls). Barlow liked the idea of the new team entering an abandoned Firehouse and Egon appearing out of thin air in his ambassador garb murmuring in an ancient ghost language. He had spent so long on the other side he was barely able to speak English. 
- Egon's ponytail was a hold out to Fil Barlow's initial design. 
- Egon wrote Spengler's Spirit Guide by the time of Extreme Ghostbusters, but it appears to borrow a lot from Tobin's Spirit Guide.
- In Ghostbusters Issue #2 page 19, Baby Egon from "Three Men and an Egon" appears to the right of Jacquelyn and Zac.
- ↑ Egon Spengler (2009).The Real Ghostbusters- "Egon's Dragon" (1986) (DVD ts. 05:29-05:32). Time Life Entertainment.
- ↑ Egon Spengler (2009).The Real Ghostbusters- "Baby Spookums" (1986) (DVD ts. 08:32-08:34). Time Life Entertainment. Egon says: "My mother used to call me Spookums."
- ↑ "Troll Bridge"
- ↑ Egon Spengler (2009).The Real Ghostbusters-"The Boogieman Cometh" (1986) (DVD). (DVD ts. 9:25-9:32). Time Life Entertainment.
- ↑ "Take Two"
- ↑ "Cry Uncle"
- ↑ Egon Spengler (2009).The Real Ghostbusters- "Night Game" (1986) (DVD ts. 03:27-03:31). Time Life Entertainment.
- ↑ Janine Melnitz (2009).The Real Ghostbusters- "Doctor, Doctor" (1986) (DVD ts. 09:31-09:35). Time Life Entertainment.
- ↑ Egon Spengler (2009).The Real Ghostbusters- "Don't Forget the Motor City" (1986) (DVD ts. 17:59-18:01). Time Life Entertainment.
- ↑ Eatock, James & Mangels, Andy (2008). The Real Ghostbusters Complete Collection booklet, p. 12. CPT Holdings, Inc.
- ↑ Egon Spengler (2009).The Real Ghostbusters- "Banshee Bake a Cherry Pie?" (1986) (DVD ts. 01:47). Time Life Entertainment.
- ↑ Egon Spengler (2009).The Real Ghostbusters- "Ghost Fight at the O.K. Corral " (1986) (DVD ts. 09:03-09:04). Time Life Entertainment.
- ↑ Egon Spengler (2009).The Real Ghostbusters- "Ghostbuster of the Year" (1986) (DVD ts. 08:12-08:13). Time Life Entertainment.
- ↑ Egon Spengler (2009).The Real Ghostbusters- "A Ghost Grows in Brooklyn " (1986) (DVD ts. 05:21-05:28). Time Life Entertainment. Egon says: "I have some pots at home. I used to use plants in my experiments until they all died."
- ↑ Egon Spengler (2009).The Real Ghostbusters- "Rollerghoster" (1986) (DVD ts. 01:31). Time Life Entertainment.
- ↑ Eatock, James & Mangels, Andy (2008). The Real Ghostbusters Complete Collection booklet, p. 22. CPT Holdings, Inc.
- ↑ Egon Spengler (2009).The Real Ghostbusters- "Rollerghoster" (1986) (DVD ts. 01:43-01:45). Time Life Entertainment.
- ↑ Winston Zeddemore (2009).The Real Ghostbusters- "Rollerghoster" (1986) (DVD ts. 05:36-05:38). Time Life Entertainment.
- ↑ "The Devil to Pay"
- ↑ Egon Spengler (2009).The Real Ghostbusters- "The Devil to Pay" (1986) (DVD ts. 19:01-19:08). Time Life Entertainment.
- ↑ Egon Spengler (2009).The Real Ghostbusters- "Poultrygeist" (1988) (DVD ts. 06:47-06:49). Time Life Entertainment.
- ↑ Egon Spengler (2009).The Real Ghostbusters- "The Brooklyn Triangle" (1988) (DVD ts. 22:00-22:02). Time Life Entertainment.
- ↑ Fil Barlow deviantArt 3/1/12
- ↑ Fil Barlow deviantArt 3/1/12