Almost all the actors played at least two different roles over the course of the series, since people who died first got reborn on Fire or Water in Season 3 and later on Earth in Season 4.
The 4th season episode "Midsummer's Nightmare" briefly had Brian Downey (Stanley) playing Stanley, Zev, Kai, and Puck due to some shape-shifting mischief by Titania
Billing Displacement: Jeffrey Hirschfield, the voice of 790, was never included among the main cast, despite portraying one of the four main characters and being credited in every episode.
Blooper: In "Girltown", Stanley spots something buried in the sand, and there's a long shot where you can just barely see him enter the frame and walk up the hill towards it. The next shot is of him waiting by the moth, whereupon he decides to start walking towards it.
Casting Gag: "Girltown", a quasi-socialist critique of Parliamentary democracy, has Jimmy Somerville cameo and sing a very 80s New Wave pop hit, ala his decidedly left-leaning band the Communards.
The Cast Showoff: Michael McManus is an accomplished pianist, and performed the rendition of the Brunnen-G anthem heard in "The Rock" himself.
Defictionalization: A porn star working under the name Xev Bellringer cropped up some fifteen years after the end of the show's run.
Dyeing for Your Art: It wasn't possible to get baby blue hair coloring in 1997. So Eva Habermann had to color it with Easter egg dye. "It was not at all healthy." She switched to a wig for the second season because of the damage done to her hair.
English Josh Hartnett lookalike Rupert Evans plays Midwestern boy Cleasby in Prime Ridge.
He Also Did: The show's production company, Salter Street Films, was founded by brothers Michael and Paul Donovan. Paul was the driving force behind the creation of Lexx, while Michael focused on running the business. After a series of buyouts and mergers in the early 2000s (which included Salter Street Films being absorbed into Alliance Atlantis of Due South, Earth: Final Conflict and CSI fame), Salter Street Films was relaunched as the children's animation studio DHX Media (now WildBrain), which Michael Donovan is longer CEO of (as of 2021). Their most famous show? My Little Pony: Friendship Is Magic.
Referenced by...: In Stellaris, there is an organic spaceship with the remains of its crew of three separate species.
Screwed by the Network: Not to a FOX level, but the Sci-Fi channel's commercials - and airing of episodes wildly out of order, showing all the raunchy ones back to back though they did show them in order eventually - would lead you to believe that it's porn dressed up as Space Opera. To be fair to the network, they did give us the fourth season out of fan demand when word got out it wasn't going to happen, which is more than they did for Farscape. Also, when the September 11th attacks happened during the middle of season four and a new episode was preempted for a network-spanning broadcast about it, many fans found the tribute show ultimately depressing instead of uplifting and stayed up in the hopes that the late-night encore would be the new episode; it wasn't, but instead of just re-running the previous week's show, they had the thought to re-run fan-favorite Brigadoom.
Eva Habermann could've been Zev for the entire run; she left because news about season two was taking so long that she had to choose between taking other work or banking on the show getting picked up.
On a smaller scale, the original plan for Lyekka Vs Japan was to have Wist from Eating Pattern come back, but the actress was unavailable.
"Midsummer Nightmare" was intended to be filmed at Stonehenge, but the location was unavailable due to restrictions imposed during the 2001 outbreak of foot and mouth disease in the UK (lampshaded in the show), so they had to settle for the decommissioned Battersea Power Station instead.
(lampshaded in the show), so they had to settle for the decommissioned Battersea Power Station instead.