The episode was recorded on July 26 and 31, 1989.
Dave Coulier recorded alone on July 31, 1989.
The first draft was completed on June 20, 1989.
In a draft of the episode's script, Ed Zeddemore sent the train set that Winston and Slimer play with in the beginning of the episode. Ed and Winston put it together when the latter was a child. It was Winston's first and best train set.
In the first draft, the Ghostbusters distracted the Tag Monster by launching Slimer at his head instead of ignoring him like in the episode then Ray pops out from a pile of leaves near the Monster's feet and tags it.