Jimmy is a friend of Ron Alexander.
While playing billiards at a bar, Jimmy and Ron began discussing the Ghostbusters. Jimmy wasn't as interesting in the business as Ron was. He highlighted the fact they employed nuclear backpacks and didn't see how Ron could get access to their equipment schematics. Once Ron got a working prototype completed, Jimmy expressed his reservations but Ron went on with the test. Suffice to say, it was back to the drawing board. The next year, Jimmy accompanied Ron to the Firehouse. While Ron relished in finally being hired to the Ghostbusters, Jimmy mused all it took was some prison time. Ron brushed him off and advised him to go back to his car before it was towed. Ron never stayed in touch with Jimmy after he relocated to Chicago. 
Ron still had his key to Jimmy's uncle's apartment and used the space for the construction of his and Holtzmann's Remote Access Teleportation Unit. Jimmy was annoyed Ron didn't even give him a head's up he was in town. Ron filled in Jimmy on how the Ghostbusters came to have teleportation technology but Jimmy suspected he stole something and was back to puttering about in his uncle's apartment. Ron introduced Jimmy to Holtzmann. Holtzmann explained she came from beyond. Jimmy was naturally confused. Holtzmann confirmed she was a woman with several degrees, and only two were made up. Ron informed him she was a Ghostbuster from another dimension. Jimmy was aghast she probably had a God complex too. Ron told Jimmy he planned to open the teleporter to tourists and charge a fortune. They proceeded to test their unit. Ron and Holtzmann went to Tip-Top for lunch but she noticed weird readings on the prime universe's P.K.E. Meter and her P.K.E. Meter that weren't ghost-related. Ron could care less but he soon was hailed on the walkie talkie by Jimmy, who alerted him the teleportation unit was acting weird. Ron and Holtzmann bolted and teleported back to the apartment. They watched as their invention generated several portals at once. Ron pulled the plug on the unit and turned it off. He guessed both teleporters were on at once then insisted they could fix the glitch. Jimmy prayed to God for strength.
Jimmy appears to be rather skeptical.
- According to Ron, Jimmy always has bad feelings about things. Hence, Jimmy never had any fun in college. 
- On the Subscription Cover of Ghostbusters Volume 2 Issue #1, Jimmy's photo is above Janine.
- Jimmy's bio in the Dramatis Personae in Ghostbusters Crossing Over Issue #1 reveals reveals he is Ron's oldest (and possibly only) friend. 
- Jimmy is a fan of a science fiction television series involving parallel dimensions. 
- Jimmy's bio is in the Dramatis Personae of Ghostbusters Crossing Over Issue #2 but he doesn't appear in the issue.
- ↑ Jimmy (2018). IDW Comics- "Ghostbusters Crossing Over Issue #1" (2018) (Comic p.1). Jimmy says: "I haven't heard from you since you moved to Chicago!"
- ↑ Ron Alexander (2012). IDW Comics- "Ghostbusters Issue #9" (2012) (Comic p.8). Ron says: "You always have a bad feeling about things. It's why you never had any fun in college."
- ↑ Dramatis Personae (2018). IDW Comics- "Ghostbusters Crossing Over Issue #1" (2018) (Comic Dramatis Personae page). Narrator says: "Ron's oldest (possibly only) friend."
- ↑ Ron Alexander (2018). IDW Comics- "Ghostbusters Crossing Over Issue #1" (2018) (Comic p.1). Ron Alexander says: "... And then Jimmy, he of the tall hair realized there are a lot of dimensions out there - just like that TV show you're always watching -- and we finally have the technology to visit them."