Throughout the ages, Marduk has traveled from city to city in hopes of settling down permanently. He is known to have been to Babylon, Athens, Rome, Peking, Paris, and London.  When Marduk was in ancient China, he thought he had lost Tiamat indefinitely. 
In the mid-1980s, Marduk manifested in New York City and traveled around assuming different forms. He concluded New York City was the ultimate city and wanted to settle down. A pair of police officers were caught in the earthquake caused by Marduk's arrival to this plane. The earthquake flipped their patrol car, 49er5, over onto its roof. After extricating themselves uninjured and radioing back to control, they noticed eerie lights flashing below street level. One of the officers grabbed his 35mm camera and managed to take a snapshot of a mysterious glowing reddish colored orb just as it rocketed out of a subway station access and off into the Manhattan night skyline.
Both officers were unsure of exactly what they had just been witnessed. The younger officer with the camera was ordered back to the police station on foot to have the picture developed immediately. The now developed photo managed to capture an image of Marduk, in his true form, and was shown to the Ghostbusters by the same two policemen. The next day, as a dock worker, Marduk saved steamer at the Midtown Pier after it crashed into another ship. Through the use of a computer version of Tobin's Spirit Guide, the Ghostbusters eventually identified him as Marduk, but a bigger problem presented itself when Tiamat manifested in Central Park.
The Ghostbusters traced Marduk's emanations north to Grand Central Station and attempted to find him with their P.K.E. Meters. He took on many forms but after a long chase they easily found him when he unwittingly assumed the form of Santa Claus when it wasn't Christmas. Marduk had finally agreed to let the Ghostbusters help him to capture his enemy. When Tiamat was finally destroyed, The Ghostbusters believed that Marduk was also destroyed because the two beings couldn't exist without one another, an ecto-symbiosis.  This was invalidated when a horse Winston Zeddemore rode during the bust turned into a blonde police officer, tipped his hat to the departing Ecto-1, turned, and walked away.
Being the god of the city, he can assume the form of any citizen, be it a human or an animal. He did this by expelling red energy, which he could also use offensively, capable of knocking all four Ghostbusters on their backs.
Marduk (in his true form) possesses four eyes and four ears granting him superior perception to those of normal human beings. He could also breath fire, although he was never seen doing this offensively.
His titanic limbs are endowed with bristling muscles giving him tremendous strength, enough so that he engages his dragon enemy in unarmed immortal combat and can lift a ferry boat out of the water.
Marduk has the ability to fly.
At Grand Central Station, the Ghostbusters set their P.K.E. Meters to "Infinite" to accurately detect Marduk without interference from psychic background noise and local specters. 
- The snapshot of Marduk was an actual photograph in real life which was rotoscoped into this animated cartoon episode. 
- The scene of Marduk waking up on a park bench is taken directly from the opening of the 1937 film "Dead End"
- Marduk assumes 12 forms in the episode.
- A dapper gentleman
- A dock worker
- A man asleep on a park bench
- A sailor
- A night watchman
- A nun
- A child with boom box
- A businessman
- Santa Claus
- A man in a trench coat and fedora
- A horse
- A police officer
- On page 18 of Ghostbusters: Get Real Issue #1, on the white board, on the right is a photo of Tiamat.
- On page 11 of Ghostbusters: Get Real Issue #3, a photo of Marduk appears on the right side of the whiteboard.
- ↑ Egon Spengler (2009). The Real Ghostbusters - "I Am the City" (1987) (DVD ts. 08:05-08:06). Time Life Entertainment. Egon says: "Marduk, Babylonian god of the city."
- ↑ Egon Spengler (2009). The Real Ghostbusters - "I Am the City" (1987) (DVD ts. 08:33-08:36). Time Life Entertainment. Egon says: "Marduk had an eternal adversary, a giant five headed dragon named Tiamat."
- ↑ Marduk (2009). The Real Ghostbusters - "I Am the City" (1987) (DVD ts. 15:46-15:50). Time Life Entertainment. Marduk says: "Babylon. Athens. Rome. Peking. Paris. London. I seen them all."
- ↑ Marduk (2009). The Real Ghostbusters - "I Am the City" (1987) (DVD ts. 16:10-16:12). Time Life Entertainment. Marduk says: "I lost him in ancient China."
- ↑ Egon Spengler (2009). The Real Ghostbusters - "I Am the City" (1987) (DVD ts. 20:53-20:56). Time Life Entertainment. Egon says: "I suppose they couldn't exist without each other. Ecto symbiosis."
- ↑ Egon Spengler (2009). The Real Ghostbusters - "I Am the City" (1987) (DVD ts. 04:40-04:44). Time Life Entertainment. Egon says: "I checked the line recorders. The psychic energy reading went off the scale."
- ↑ Egon Spengler (2009). The Real Ghostbusters - "I Am the City" (1987) (DVD ts. 13:08-13:14). Time Life Entertainment. Egon says: "Use your P.K.E. Meters. Set them on "infinite." That way, they won't be distracted by psychic background noise or local specters."