- Acting for Two:
- Mark Hamill not only voices Snakebite Scruggs, but also Shaggy and Scooby's airport supervisor, the ghosts of Morgan Moonscar and the Confederate general, and a plantation worker.
- In the Latin American Spanish dub, Scooby-Doo, Mr. Beeman and Jacques are all voiced by Francisco Colmenero; and Ricardo Tejedo voices Fred Jones and Snakebite Scruggs.
- Frank Welker not only voices Fred but also Simone's cats, Snakebite's pet pig Mojo, and multiple zombies.
- Actor-Shared Background: Jim Cummings actually did serve on a New Orleans riverboat when he was younger, and the time he spent in the city is what made him one of the few voice actors capable of doing a convincing Cajun accent. Jacques even looks a little like him.
- Celebrity Voice Actor: Adrienne Barbeau provides the voice of Simone. She later branched out and did more voice acting in the years after this.
- Directed by Cast Member: The Latin American Spanish dub was directed by Genaro Vásquez, the voice actor for Beau Neville.
- Fake American: Canadian-born Tara Strong affects an American Southern accent for Lena.
- In Memoriam: To Don Messick, the original voice actor for Scooby-Doo who had passed away the previous year due to complications from his second stroke, just before recording began.
- Keep Circulating the Tapes: The two Skycycle songs were never properly released (a hokey synthesized version appeared on the soundtrack for Scooby-Doo! and the Witch's Ghost). The only "clean" versions that exist are played during the end credits.
- The Original Darrin: After being voiced by Carl Steven in A Pup Named Scooby-Doo, Frank Welker returned to voicing Fred for this film, and continues to do so to this day.
- The Other Darrin:
- The Other Marty: Heather North was originally planned to reprise her long-running role of Daphne, but during recording, she was replaced with Mary Kay Bergman after producers decided they wanted a fresher take on the role. North would still later voice Daphne two more times, in Scooby-Doo! and the Legend of the Vampire and Scooby-Doo! and the Monster of Mexico.
- Playing Against Type: Tara Strong usually voices Genki Girls or Keet boys. Even though Lena is probably the least evil of the three villains, it's easily the most evil role Tara has ever voiced.
- Recycled Script: The concept was originally a unfinished SWAT Kats episode, "The Curse of Kataluna" (which would've involved a Succubus). Suddenly, the Darker and Edgier tone (and all the cat-related motifs) makes a lot more sense. (Parts of it were also recycled by the writer, Glenn Leopold, for the season two episode "Eclipse" for Jonny Quest: The Real Adventures.)
- Role Reprisal:
- Frank Welker returns to voice Fred for the first time since 1984 — admittedly this is the first time Adult!Fred had appeared in any media since 1984. Welker is the only one of the original voice actors to do so (though Heather North was planned to return, and it's heavily implied Don Messick would also have returned had he lived).
- BJ Ward, who voices Velma here, previously voiced her in the Johnny Bravo crossover episode a year earlier.
- Unintentional Period Piece: Shaggy and Scooby would not have gotten away with their airport antics (especially Scooby constantly sniffing and barking at people's baggage) in a post-9/11 world. The camera is also very late 90s, and the gang losing it to quicksand means that they have no footage at all for Daphne's show; these days everything would be digital and backed up on computers and hard-drives easily after each filming day - as opposed to having to get the tapes processed back then. Also, Simone and Lena's scheme to trap people on the island would be harder to pull off when most people would have mobile phones these days and could call for help.
- What Could Have Been: Tara Strong says that she and the other voice actors were originally going to speak in Cajun accents. She herself says she found the accent very difficult and Jim Cummings, who learned it around the time of his residency in Louisiana, said they didn't sound authentic, so they just went with typical Louisiana accents.
Trivia / Scooby-Doo on Zombie Island