Extreme Ghostbusters/YMMV


 * Complete Monster: The Grundel, again.
 * There was also the being known as Piper, a one-shot villain from the episode "The Pied Piper of Manhattan". He's responsible for a sudden plague of ghosts in New York that he unleashes in order to play the hero when he repels them with his flute. When the Mayor attempts to pay him according to contract, Piper reveals he wants more. After his requests for a statue of himself down 5th Avenue and an office in city hall are denied, Piper uses his flute to hypnotize the children of the city and tries to force them to drown themselves, gloating the mayor will "rue the day he refused to pay the Piper." What seals the deal is that when the Ghostbusters intervene, Piper has no compunction using the kids as human shields in their fight.
 * Surt, from "Slimer's Sacrifice", is a godlike ghost who seeks to bring about the apocalypse. His minion Fenris prepares his coming by turning three humans into his vanguards. When Slimer ends up in the containment unit, Surt demands to know how Slimer got in there and hints that he is going to torture the information out of him. When Surt senses Eduardo's presence, he allows him to rescue Slimer and waits for him to open the exit to the containment unit so he can follow them. When Eduardo realizes Surt's plan and destroys the remote that will open the exit, Surt activates a spell he placed on Slimer to make him cut Eduardo's oxygen tank, before releasing Slimer from his control so he can realize that he just doomed his friend and be left to watch him suffocate and die, with Surt promising to return and torture Slimer after Eduardo dies.
 * Fridge Brilliance: Kylie's proton pack is smaller and differently shaped because she's much smaller and physically less strong than her teammates.
 * That, and she's also wearing the larger Trap on her back!
 * Funny Aneurysm Moment: The second part of the series finale episode, "Back in the Saddle," has one scene in which the Twin Towers are being devoured by the blob-like ghost that's invading New York City.
 * Germans Love David Hasselhoff: The show was quite popular on Continental Europe to the level that it has a few video game adaptations.
 * Rescued from the Scrappy Heap: Slimer has a smaller role here than in The Real Ghostbusters, and is therefore much more tolerable.
 * Additionally, his characterization is more in line with the early days of the prior series. Rather than act like a Cousin Oliver with a dash of We're Still Relevant, Dammit!, he behaves the way that made fans like him in the first place: a Big Eater that speaks incoherently and tries to do his best to help his friends.
 * We're Still Relevant, Dammit!: Actually, despite putting teenaged characters front and center, the series overall tended to avert this. Still, the title of the show does seem to scream this trope.
 * Fridge Brilliance: Ah, but, the Ghostbusters themselves are not "extreme." The *ghosts* are.