Ghostbusters Reboot: 29 Easter Eggs, References & In-Jokes
20. Holtzmann Is Egon
Looking at the design of Egon Spengler from the classic Real Ghostbusters animated series, it seems obvious that Holtzmann is based on him.
The pair both have outrageous glasses, dress eccentrically and have wonderful, quirky coiffured hairstyles. It's definitely not accidental.
It's actually an accidentally pertinent parallel to bring The Real Ghostbusters into it: that show went through a tonal change in its third season as characters were softened and a different audience was sought. In contrast, the show tried to be less scary (culminating in a stronger focus on Slimer by the end), but it seems like a worthwhile comparison to bring up.