Poso wanted to ascend to a supreme level of ghost authority called "The Ghostfather" by having his goons abduct Janine and Louis and then using them to threaten the Ghostbusters into handing over all their equipment.  With the equipment at his disposal, he could control every ghost on the East Coast.  Poso had a sidekick named Shifter, who was captured by the Ghostbusters two weeks ago due in part to Poso's scheming.  Shifter was extracted out of the Containment Unit to help them. However, Egon Spengler knew Shifter would try to pull a fast one, so he used a device to use on Shifter that would pull him like a magnet if he tried to fly away.
Shifter told the Ghostbusters Poso's plans and he went to Poso's lair in Ghost Town, New Jersey with Peter Venkman to end the crook's scheme. Janine and Louis were saved. Shifter then used the device controlling him to help capture Poso. He removed the collar part around his neck and had it stuck on Poso's wrist. Shifter then activated the control and tossed it in the trap, causing Poso to fly into the trap and get captured. After Poso was trapped, Shifter was granted the privilege to roam around free.
Tobin's Spirit GuideEdit
The home computer version contains a mugshot of Poso, an ID# of KL-2793-001-45. His attributes are Criminal Mastermind, Firebrand Third Level (Pyrokinesis), Evil Overlord Sixth Level, and Grand Forger 12th Degree. he is described as ruthless, evil, deadly, bad, dangerous, and mean. Poso is classified as a Class 7 Organizer. 
Poso loosely resembles Jabba the Hutt from Star Wars, except he is dark purple, has four arms, wears gangster clothes, and has a tail that splits in two near the end. Only one of the tail tips resembles a rattlesnake's rattle.
Poso's demeanor and M.O. is essentially that of the stereotypical 1930's gangster.
- It is highly possible Poso was inspired by Jabba. Both characters are ambitious, high-ranking, and inhuman crime lords with many underlings.
- On page one of Ghostbusters Volume 2 Issue #12, Poso makes a non-canon cameo on a wanted poster.
- On page 15 of Ghostbusters Volume 2 Issue #18, Poso's file makes a non-canon cameo on the computer.
- ↑ Poso (2009). The Real Ghostbusters - "Partners in Slime" (1989) (DVD ts. 05:07-05:14). Time Life Entertainment. Poso says: "Youse got 'til midnight to turn over the whole Ghostbusters operation to me, Boss Poso."
- ↑ Shifter (2009). The Real Ghostbusters - "Partners in Slime" (1989) (DVD ts. 09:21-09:23). Time Life Entertainment. Shifter says: "Poso wants to be the Ghost Father."
- ↑ Shifter (2009). The Real Ghostbusters - "Partners in Slime" (1989) (DVD ts. 09:25-09:30). Time Life Entertainment. Shifter says: "Yeah, man. The big boss. With your ghostbusting gear, he could control every ghost on the coast."
- ↑ Shifter (2009). The Real Ghostbusters - "Partners in Slime" (1989) (DVD ts. 18:57-19:00). Time Life Entertainment. Shifter says: "He's the creep who got me busted in the first place."
- ↑ Egon Spengler (2009). The Real Ghostbusters - "Partners in Slime" (1989) (DVD ts. 05:33-05:35). Time Life Entertainment. Egon says: "Poso. A Class 7 Organizer."