Egon Spengler does not have much social ability, as demonstrated by his stiff interactions with the Ghostbusters' secretary Janine Melnitz, and his reliance on Peter Venkman as spokesperson for the group. Spengler is the most serious and rigid member of the team. Of his hobbies, Spengler states that he collects "spores, molds, and fungus", and claims that, as a child, the only toy he ever had was "part of a Slinky", which he straightened out. As implied in the first movie, Spengler apparently is a sugar junkie, due to his affection for sweets and candy. According to the 2009 video game, Spengler
Egon Spengler intellect switched with Slimer's. He has however, ceased his sugar junkie ways, only to briefly be tempted by a candy store when in Slimer's body (a likely fact that Slimer was an overt glutton). It is revealed in "The Boogieman Cometh" that, as a child, Spengler was stalked by the boogieman, a supernatural monster that fed on the fear of children and hid in their closets, and was particularly fond of Spengler's fear; it was these encounters with the creature that inspired Spengler to study the paranormal, and as an adult, he would battle the Boogieman twice and defeat him.