This animated series is a continuation, a sequel of sorts, to Les vrais chasseurs de fantômes (1986). It picks up some seven-years later after the original 'Ghostbusters' disband/break-up, supposedly due to lack of paranormal activity. All the ghosts & goblins simply up and vanish. Suddenly, when strange things/creatures start surfacing again in New York City 1997, 'Egon' recruits an all-new team of 'Ghostbusters' comprised mostly of his best physics class, university students. One of the best episodes was the return of the original "Real Ghostbusters." They appeared in a two-part episode fully dressed in their old-school jumpsuits and carrying their traditional proton packs. Except this time their true age began to show. They began to act/move a little bit slower.
The producers and voice directors insisted that the voice actors perform fairly naturally rather than over the top. They also wanted the entire cast to be present at recording sessions instead of recording them separately. Since most of the actors were also doing voice-work on other shows during the day, the recording sessions for Extrêmes Ghostbusters (1997) were mostly scheduled at night.
Samhaim, a recurring villain from Les vrais chasseurs de fantômes (1986) appears during the opening and end credits, but is never featured in any of the episodes. He was however released as an action figure in Trendmaster's Extreme Ghostbusters toy line.
During development of the show, a deal was made with toy company Trendmasters to produce a tie-in toy line. Trendmasters really wanted the show to be titled "Super Ghostbusters", but the producers found that title a bit too "soft" and came up with the more edgy sounding Extrêmes Ghostbusters (1997).
There were plans to give Slimer a mischievous goblin companion named Gnat, but they were soon scrapped.