Will admit to not being particularly crazy about "Revenge of the Man Crab" on first watch. On paper, the story and the monster sound quite silly and at the end of my first watch years ago there was not an awful lot that stuck out that much other than the unintentional goofiness. The episode was rewatched as part of my rewatch of the whole of 'Scooby Doo: Mystery Incorporated' (which is still to me one of the best Scooby Doo shows) and some of the episodes did fare better on rewatch.
"Revenge of the Man Crab" was one of those, actually thought on rewatch that it was very good which was a real surprise. And the story and villain are far less goofy and less stupid than they sound, as the synopsis is not that inspiring or easy to take seriously and the villain's name is enough to induce unintentional laughter. This is a case of not judging something by its cover, "Revenge of the Man Crab" actually to me was very entertaining and had the right amount and type of atmosphere.
The animation is still very colourful and atmospheric with a lot of rich background detail. Loved the look of the villain, the upside down visuals really do catch the eye and are very clever. The music has personality and is not discordant with the action, fitting the show's darker tone while not being over serious. Absolutely loved how the setting was used, with the caverns having a feeling of old Scooby Doo which was great.
Also liked the villain a lot, didn't on first watch but when looking past the name he is very cool and creepy, with the upside down visuals making him stand out. The humour was funny, while there is vintage Shaggy and Scooby humour Fred digging was funny too. The more serious elements with the ongoing mystery intrigue and not done in too serious a way, easy to do for a show with as dark a tone as this does. The story always intrigues and entertains, loved the atmosphere while the reveal isn't too obvious or confusing. The character writing for the gang is with little issue and can't fault the voice acting.
It's not a perfect episode mind. Didn't like Velma's bossiness which the writers did overdo, Shaggy did not deserve to be treated in that way.
Otherwise, very good and a lot better than remembered. 8/10.