Heroes • Ren (voiced by
George Newbern) – The prince of the once-grand kingdom of Octopon and the main protagonist of the series. Ren was raised by a
lighthouse keeper on the outskirts of his homeland, unaware of his destiny and heritage. He wields the broken sword that belonged to his father in its whole form. By the second half of the first season, he freed one-half of the world from the Dark Water. • Niddler (voiced by
Roddy McDowall in the miniseries,
Frank Welker in the TV series) – A
monkey-
bird who once belonged to Bloth until he escaped by aiding Ren's escape from the pirate captain. He hails from the island of Pandawa. Niddler is usually depicted as a little greedy and constantly ravenous for food, his favorite food being minga
melons, but he likes Ren and his ability to fly often comes in handy. • Tula (voiced by
Jodi Benson) – She is an ecomancer with the ability to control the elements and biological life, both sentient and non-sentient, as well as a natural affinity towards nature and animals. She is headstrong and often flusters Ioz. Tula is introduced as being a simple barmaid, but she stows aboard Ren and Ioz's ship, claiming she "wanted to get away from the drudgery of life on land." It's soon revealed that she's a character with many secrets. • Ioz (voiced first by
Héctor Elizondo) – A rogue and pirate, he joins up with Ren initially for the promise of treasure. Throughout the seasons, his character matures and he becomes fond of Ren and his idealism, evolving into a protective brotherly figure to him and often risking his life for Ren and the quest for the Treasures. He continues his attempts at getting rich quickly but is mostly unsuccessful. Ioz also has a younger sister named Solia, who appears in the series. Like Niddler, he originally worked for Bloth, but "it ended ugly" according to him.
Recurring characters • Zoolie (voiced by
Dick Gautier) – A jolly, redheaded rogue who runs a gamehouse in Janda-Town. He and Ioz crewed together on Bloth's ship the Maelstrom. Though not a main character, he does make recurring appearances by offering advice and assisting Ren and his friends whenever they make port in Janda-Town. • Teron (voiced by
Dan O'Herlihy) – He is a supreme ecomancer who sprouts roots from his body to replenish himself from a portable supply of native soil when he is away from his homeland, Andorus. He is first seen in the series as a prisoner on Bloth's ship, and Bloth uses his power for evil, in turn exhausting the local environment and its positive life energy. Tula has great respect for him as an ecomancer, and she was sent on a mission to bring him back to Andorus to heal the Dark Water-ravaged island. Teron also helps Tula adjust to her new powers as an ecomancer when they first manifest themselves.
Villains • Bloth (voiced by
Brock Peters) – The ox-sized, humanoid pirate captain of the feared pirate ship
Maelstrom and one of the primary antagonists of the series. Bloth is after the Thirteen Treasures of Rule to control all the Dark Water in the world and in effect Mer itself. He destroyed Primus's fleet seventeen years prior to the timeline of the show and captured Primus and his aide Avagon, though the seven captains accompanying Primus were able to escape with the Treasures. Bloth has since been hunting them obsessively and destroying every remnant of the House of Primus just as obsessively, including killing every heir to the throne of Octopon that he could find and ravaging and pillaging the ailing city. He held Primus captive for seventeen years before the old man escaped back to Octopon and to Ren. Upon learning that Primus has a son, he transferred his fanatical hatred of Primus to Ren. Bloth began to hunt the boy across the twenty seas of Mer in order to capture the Treasures and to kill Ren and the house of Primus. In the second half of the first season, he makes an uncertain and untrusting alliance with Morpho, a major agent of the Dark Dweller. • Constrictus - A crawling horrifying worm-like creature in the bowels of the Maelstrom who is Bloth's pet. It is described as having a mouth full of teeth and tentacled limbs that are tipped with poisonous fangs. Anyone who displeases Bloth gets thrown to the Constrictus. • Mantus (voiced by
Peter Cullen) – Bloth's second-in-command with long limbs, hands, and feet and
insectoid-like traits. He offers his cool and calculating personality as a battle strategist for Bloth's fleet. • Konk (voiced by
Tim Curry) – A short, fat half-barefoot pirate with
bulldog-like jaws who works for Bloth. He lost his right leg thanks to a close encounter with the Constrictus. For a long time, Konk was the only one to ever survive being thrown to the monster. Although not particularly smart, Konk possesses more bluster than most of Bloth's crew and is always trying to win Bloth's praise. • The Lugg Brothers (voiced by
Earl Boen and
Frank Welker) – Two huge, dimwitted super-strong siblings who are members of Bloth's crew. One Lugg Brother has no hair and a long braided moustache and the other has blonde hair. They try to assist Konk, but their stupidity makes them more of a hindrance than anything. The Lugg Brothers only make appearances as main characters in the first five episodes of the show. • The Dark Dweller (voiced by
Frank Welker) – One of the primary antagonists of the series. The Dark Dweller is a powerful, evil creature that created the Dark Water. He had the Treasures originally scattered because their power is the only thing capable of opposing him and his evil master plan to swallow Mer in Dark Water. • Morpho (voiced by
Neil Ross) – A servant of the Dark Dweller and the leader of his worshippers, the Dark Disciples. He joins forces with Bloth and serves as the above-water liaison for the Dark Dweller, so that they can aid each other in their mutual goal of killing Ren and his friends, though they have two very different goals for the Compass and Treasures. He was an
alchemist who was doing research on the Dark Water when the Dark Dweller captured him and transformed him so that he was no longer fully human, making him into an eternal servant. He possesses a tentacle in place of one arm, and half his body has been reshaped to resemble an amalgam of deep-sea creatures. He refers to himself as a creature of two worlds, Ren's and the Dark Dweller's. • Joat (voiced by
Andre Stojka) – A pirate and the previous owner of the Wraith. His ship was stolen by Ioz. He uses his metal claw in place of his left hand mercilessly in battle. Originally slated to have a larger role in the series, his only major appearance was in "The Soul Stealer." ==Ships==