The Proton Bazooka is a modified bazooka that releases a concentrated stream of protonic energy.
The Real Ghostbusters
The Ghostbusters were once trapped in their dreams by The Mean Green Teen Machine. Eventually, they reunited but the ghosts proved too formidable. Peter Venkman even pulled out a giant bazooka but Egon Spengler stopped him before he could fire. Egon outsmarted the ghosts by offering them a giant pizza then trapping them.
IDW Comic Series
The Proton Bazooka is a new piece of equipment built by Egon Spengler. The bazooka was loaded on Ecto-1a when Peter Venkman and Kylie Griffin responded to a call in Mamaroneck. Peter became the first person to use the Proton Bazooka when he used to destroy the Mamaroneck Ghost Train with one blast. Kylie attempted to leverage a 50% cut of the fee in exchange for not telling Egon it was used but Peter decided to let Egon suffer a little heartbreak. As Peter walked off with the used Trap, Kylie was left to lug the bazooka back to Ecto-1a.
Peter used the Proton Bazooka as a temporary fix to buy some time and dispersed Chi-You's spectral form in Chinatown. While Chi-You reformed, the Ghostbusters and Turtles restored Casey Jones to normal and took him back to the Firehouse. In the battle against The Sandman in a dream state, Peter visualized the Proton Bazooka and opened fire with it. During an overlap of two dimensions, the Ghostbusters met another team. On the ride to an active case on Ellis Island, the Proton Bazooka was among the equipment they brought with them. Jillian Holtzmann was smitten with it and couldn't wait to find out what the proton yield was. Erin Gilbert got an idea to close the dimensional tear above the island with a controlled explosion and suggested rigging a trap. Ray was concerned not even the Megatrap would be enough to fully discorporate the Megaspook Jr. entity. Erin took the Proton Bazooka and fired on it. After she made a direct hit, several Pirate Ghosts that formed the entity flew out of it. Holtzmann was upset with Erin because she called dibs on it first. She vowed there would be reprisals.
The version seen on The Real Ghostbusters was utilitarian and was different shades of gray whereas the IDW version had a color scheme and design more reminiscent of the same motif as the Traps.
- IDW Comics