Head and Body- LiftTicket
Legs- General Hawk

Elbow pads-BBI figure
Proton Pack- Various pieces from Dreadnok packs and accessories
Wand- Torch's flamethrower and Lightsaber handle
Energy beam-McFarlane toys Frankenstein playset
Trap-SAW ammo box, wire, plastic piece and center section from Ripper's jaws of life

This was a custom that came about by accident. I was waiting for some parts to come in and finish another custom when I was looking at some extra parts. I discovered that, in the right design, I can use the Dreadnok parts to recreate a proton pack (though not an exact copy). Once done with the pack I searched for a figure that closely ressembled a Ghostbuster. Amazingly, Lift Ticket looks like Bill Murray. I swapped the legs with Hawk's to make the figure thinner (why is Lift Ticket so thick in the thighs?).
I gave the character the code name Ectohunter, so that I am not copying the Ghostbuster name and too give him an identity unique in the GI Joeverse. The file name is Dr. Peter Venkman still, since he was the best Ghostbuster. This explains where Dr. Venkman went during the Extreme Ghostbusters episodes.