Edited for Syndication: Toon Disney initially banned the episode "Deadly Force" because the episode revolved around Elisa's near-fatal shooting by Broadway (who was playing around with her gun). In 2002, Toon Disney finally showed the episode, but the part where Elisa gets shot uses a fake zoom-in on Elisa's face to cover up the blood around Elisa's torso. A later scene in this episode has Broadyway sobbing, but the sound effect lasts noticeably longer than the clip used.
On Toon Disney and the VHS video release of "Awakenings, Part Two," Xanatos's line "Pay a man enough, and he'll walk barefoot into Hell," was cut. The DVD version has the line uncensored.
In Toon Disney airings of "The Reckoning," Fang saying "Kinky" after witnessing Demona's transformation into a human is cut.
Executive Meddling: The Retool of the third season was caused by Disney replacing the entire production team. There's also the matter of the higher fees that caused the comic's cancellation.
Word of God says that the trio's motorcycle and helicopter were mandated by higher-ups who wanted to be able to sell them as toys. Of course, the motorcycle blew up within five minutes of its debut, and the helicopter showed up in one episode and was then never mentioned again...
Another positive example: The Eye of Odin was introduced as a tie-in to the Sega Genesis game, yet it led to a whole raft of plots.
Laura San Giacomo's agent refused to let her be credited for the role of Fox, believing it would damage her reputation to be on an animated show.
It was sometimes joked in fandom at the time that the casting director had set up a booth outside the Next Generation wrap party.
Unfortunately Sisko (Nokkar) and Geordi (Anansi) were hidden under heavy modulation. The latter was also a very recognizable extra in the same episode, though.
Jeff Bennett (Brooklyn, Owen, Magus, and many others) and Kath Soucie (Princess Katharine, Maggie The Cat, The Weird Sisters, and many others) deserve special mentions here due to the fact that they did roughly around 100+ characters each.
Biff! You cleaned up your act and became a good cop! ...And dyed your hair red!
A funny non-English example in the Retroactive Recognition area. If you watch Pan's Labyrinth and then listen to the European Spanish dub of the series, you'll recognize Pablo Adán, the Faun's voice, as Goliath.
Jossed: Due to having so much Word of God around, this has happened many times, on issues such as gargoyle customs and breeding habits, Elisa and Goliath's ability to reproduce, Lexington's sexuality, Katana's physical appearance, etc. Looking at older fanfics can sometimes be a very strange experience...
Keep Circulating the Tapes: While Season One and the first half of Season Two were released on DVD, the rest of the series remains in limbo thanks to poor sales. Disney went a step further, censoring episodes for violence, usage of guns, and in one case, a comment from Fang that was too racy (the "kinky" comment mentioned above). Some of the uncut episodes haven't been seen since 1997, although there is a video that has most of the major edits.
The second half of season 2 is now on dvd ... exclusively to members of Disney's Movie Club.
Line To God: Greg Weisman has this in the form of the "Ask Greg" section of fansite Station 8. Notable for at least two reasons: one, that Weisman will answer any and all questions submitted to the site given enough time (so long as they meet the site's guidelines), and two, that the site has been in more-or-less constant operation since 1997.
Overall, this has led to a searchable archive of well over 14,000 answered questions since Station 8 first opened. This may account, at least in part, for the truly massive smattering of Word of God entries on this show's pages.
Name's the Same: Some viewers may snicker at the terrifying deep voiced cyborg gargoyle when they learn he shares his name with a popular ice cream franchise.
Schedule Slip: The comic books. It's almost - almost - enough to make you glad SLG had to drop the series; it deserves better.
Season One was released on DVD in 2004, and Part One of Season Two was released in 2005. Part Two of Season Two was not released until 2013!
Disney never had any idea what to do with this series, they scheduled it once a week (on Fridays) as opposed to every day like the other programs on the Disney Afternoon block. The reason being because there were only thirteen episodes for Season One, they would've burned through the whole season in two-and-a-half weeks (assuming every episode was ready to air before the premiere, which they weren't).
Production was jerked around for Season Two, with the order for 52 episodes not being firmly settled until some weeks into starting, hamstringing them a bit. This is why there are so many gaps in premiere air dates (There would've been gaps anyway due to the volume of work, but Weisman has noted they lost extra time they could've used regardless).
They came up with downright bizarre ideas for the toy line; there's no Pack action figures, but you can have Bronx dressed like a winged metal lion for some reason. The multi-part premiere episode was packaged with a board game for some reason.
Talking to Himself: Goliath and Thailog; the Archmage and his future self, as well as several minor characters voiced by the main cast.
Considering that Jeff Bennett and Kath Soucie did 100+ character voices each, this is pretty much a given. A quick example would be that Jeff Bennett was Brooklyn and most of the thugs he fought, and Kath Soucie was Princess Katharine and Ophelia.
Speaking of things that Mike Mignola worked on, according to the introduction to one of the Hellboy Animated tie-in comics the project that eventually became Gargoyles actually began life as a Hellboy cartoon.
The series was originally conceived as an action comedy, more akin to Disney's Gummi Bears series than the show it eventually became.
A Direct-to-Video movie was in the works. "City of Stone" was originally pitched as this and while liked, it was turned down as a movie because (as Weisman conceded) the main cast only play supporting roles. "Hunter's Moon" was subsequently conceived, but a video release was scrapped altogether and it became a three-parter.
On a related note, "The Reckoning" was to be a two-parter and the Season 2 finale. When the movie was scrapped, it was shortened to a one-parter to help make room for "Hunter's Moon" to still be produced.
Originally, there was going to be another Gargoyle at the series' start. Taking the name Ralph, he was going to be more reluctant to fight and instead spend his time watching television (a quality that Hudson ultimately inherited).
The leader of the clan was originally supposed to be a female gargoyle named Dakota, but the creators couldn't work out an interesting personality for her. Goliath ended up being created to take over the leader role, while Dakota was ReTooled into a villain, becoming Demona.
A female human was always meant to be the clan's chief ally in the modern world, but she went through a lot of development before becoming the character familiar from the show. Most obviously, she went through several names (she was Morgan for a while), and occupations (museum curator, school teacher, even Xanatos's business partner) before finally settling on Elisa Maza, police detective. Elisa was also originally supposed to be hispanic, but was changed to match her VA's racial background.
Similarly, the man who would become David Xanatos was always part of the show, but was originally concieved as a bungling, comical figure and a descendant of the character who would become the Magus (who was an Evil Sorcerer at this stage of development- the evil tenth century wizard role would end up going to the Archmage, and the modern descendant of an ancient foe role to Wolf). When the show's focus switched from action/comedy to action/drama, though, he quickly became a more familiar Machiavellian mastermind. His name was Xavier for much of his initial conception, but was changed to Xanatos to avoid confusion with another Xavier.
CBS was interested in broadcasting the Bad Guys spin-off, but after Disney took over ABC, it got canceled before any work could be done.
Word of Gay: According to many posts at the website above, Lexington was this, but it was never implied or explicitly stated in the show. This was mentioned before the comic came out.
Word of God: Creator Greg Weisman, who contributes to a fairly elaborate lexicon website outlining 1000 years worth of history for the series, including ones not yet produced. And with answers to questions ranging from politics to gargoyle sex to in-jokes.