The Proton Grenade  (also known as Ecto-Grenade) is a modified hand grenade that emits a discharge harmful to supernatural entities.
The Proton Grenades was first used against Idulnas. It proved a suitable distraction while Egon Spengler, Peter Venkman, and Winston Zeddemore rappelled from a helicopter to the roof of the Shandor Building. The yield on the grenade also left a large mark on the roof itself. Several weeks later, a Proton Grenade was used to blast a hold through a seemingly impenetrable green force field surrounding Fantastic Land. Winston used a second grenade to punch a hole through the field while he evacuated the hostages of the Hungry Manitou to safety outside the park. Months later, just before Christmas, Egon elected to remotely detonate nine Proton Grenades to pierce the P.K.E. barrier erected by the ghost of Staff Sergeant Adams. Winston trapped Adams and the barrier dissipated before Egon could set the grenades off. By the Day of the Dead the following year, Egon ran out of Proton Grenades.  During an investigation at the St. Augustine Lighthouse on August 29, led by Special Agent Melanie Ortiz, two standard Proton Grenades were brought along.
During the Proteus incident, Ray noticed the P.K.E. readings he took in the alternate Ghostbusters' dimension indicated the god had a potential susceptibility to a quantum interruption.  With a strong enough jolt of protonic energy, Proteus would become vulnerable enough to wrangle in Proton Streams.  The alternate Peter Venkman pointed out the possibility of Proteus possessing a statue again and protecting himself from such an attack. Egon presented a Proton Grenade and mused they would have to boost the yield. Over the next hour, the Egons and Rays went to work on modifications. In the battle against Proteus, both Egons armed their Proton Grenades in sync then tossed them at Proteus. Proteus was initially amused by their feeble attempts but the blast of both grenades stunned him. All eight Ghostbusters opened fire and successfully captured him in their streams briefly.
The parallel Egon utilized a Proton Grenade in Iceland to temporarily dissipate the amalgamation of Gottskalk Nikulausson and the Ghost Priests after they severed the connection between the former and the Rauoskinna. He believed Gottskalk would reform anchored to his tomb with a considerable reduction in his power base.
On August 14, Ray wired a canister of positively charged Psychomagnotheric Slime to a Proton Grenade and threw it into the River of Slime underneath Las Vegas. The resulting explosion and dissemination successfully severed Ethan Kaine's connection to the river and all buildings, except The Olive, returned to normal.  Lou Kamaka and Dani Shpak were able to trap Kaine and conclude the case.
- Ongoing Series
- Ghostbusters Get Real
- Ongoing Series
- ↑ Egon Spengler (2011).IDW Comics- "Ghostbusters Issue #4" (2011) (Comic p.4). Egon says: "Adding that to the Proton Grenades and Ray's Megatrap, and we may be able to pull this off without winding up impaled on demonic trees."
- ↑ Egon Spengler (2013). IDW Comics- "Ghostbusters Volume 2 Issue #10" (2013) (Comic p.10). Egon says: "I ran out. I'm not proud of it."
- ↑ Ray Stantz (2015). IDW Comics- "Ghostbusters: Get Real Issue #3" (2015) (Comic p.12). Ray says: "Well, those PKE numbers were off the charts, but they also indicate a potential susceptibility to quantum interruption."
- ↑ Ray Stantz (2015). IDW Comics- "Ghostbusters: Get Real Issue #3" (2015) (Comic p.13). Ray says: "If we hit Proteus with a strong enough jolt of protonic energy, we could disrupt him just enough to snag him."
- ↑ Spectral Incident Report (2016). IDW Comics- "Ghostbusters International #7" (2016) (Comic p.23). Spectral Incident Report reads: "Dr. Stantz wired a canister of positively charged mood slime to an ecto-grenade and placed it within the slime beneath Vegas; the resulting explosion severed Kaine's connection to the stored power of the slime, but also allowed the slime into the fountains at the RKO Casino."
- ↑ Kylie Griffin (2013). IDW Comics- "Ghostbusters Volume 2 Issue #7" (2013) (Comic p.19). Kylie says: "Does anyone have a grenade?"
- ↑ Special Agent Melanie Ortiz (2013). IDW Comics- "Ghostbusters Volume 2 Issue #10" (2013) (Comic p.10). Melanie says: "Not even a grenade?"