Mr. Grooberson was a summer school science teacher in Summerville and had Phoebe and Podcast as students. He met with Callie to talk about Phoebe. Callie was concerned about Phoebe not getting along with other students, and being a target for bullying. Grooberson assured her that she was a good kid and things would work themselves out. Later, Phoebe shared a item which Grooberson immediately recognized as a ghost trap, but assumed was replica prop of the Ghostbusters' equipment. He in turn showed old videos of the Ghostbusters to Phoebe and Podcast, explaining the history. Later, he discovered that the ghost trap wasn't a replica, but was the actual real piece of ghost-capturing equipment. Later, at Wal-Mart, he witnessed animated mini marshmallow men, which were quite destructive.