Sparx or SPRX-77, is the team's comedian, taking it upon himself to lighten a dark mood with a wisecrack or joke; even if it's not necessarily appropriate. He pilots the Fist Rocket 3, or the Super Robot's right hand and is easily the best pilot on the team, a fact which bolsters his already impressive ego. Yet, despite his ego, Sparx is capable of being serious when it's necessary, and harbors a fierce loyalty to his team and friends. In some occasions, it's clear that he disagrees with or resents the decisions being made, and it's this secret resentment that the Skeleton King uses to turn Sparx against his friends in episodes Object of Hate and Soul of Evil.
He's a tough, proud monkey, with a love of flying and an enormous ego. He dislikes tension, and often tries to ease it with a well-placed joke, and seems to enjoy being the comedian of the team. He doesn't take life too seriously; yet he's intelligent, and fiercely loyal to his friends. He often puts himself in harm's way in order to protect them.
He's the same height and model as the other monkeys, with red fur and silver joints. His eyes are black, and when transformed, his hands are matching red magnets.
Main weapons of choice are his magnets, which transform from his hands when he's ready to fight. With these, he can utilize electrokenisis and thereby move various magnetic objects, as well as create balls of magnetic energy. Because the other monkeys are partly metallic, Sparx' magnetic abilities make him a dangerous member of the team.
- Magna-Ball Blazer: A basic magnetic move that allows Sparx to create a ball of magnetic energy and hurl it at his opponents. The move also appears to share the name of the actual magnet hands, as they were once handheld weapons.
- Magna-Field Shield: A basic magnetic shield
- Magna-Tingler Blast: A powerful magnetic move that Sparx seems to favor, it creates red energy from both his magnets to destroy his opponents.
- Magna-Ball Beam Splitter: A powerful magnetic machine gun, in which bits of red energy fire rapidly at opponents.
- Gyro-Roll: A spinning move which halts attacks, sending them hurling back in another direction.
- Electro-Vibra Force: A basic stunning move when used on its own, this move gains power and ferocity when used in tandem with Nova's "Sting-Ring" attack.
Chiro: Chiro and Sparx are very close, and share a "best friend" type relationship due to Sparx' occasional childish behavior. The two can often be found pulling pranks on the other members of the team, or playing video games together. Sparx calls Chiro "Kid," the only Monkey on the team to have a certified nickname for their young leader. They also share a fear of swimming, as shown in Depths of Fear.
Antauri: Sparx and Antauri share a complicated, yet deep relationship. Despite Antauri's often irritation with Sparx' goofy behavior, the Red Monkey holds a bit of a Right-Hand Man role with regard to their second-in-command, reacting violently when Antauri has had his life threatened. In return, Antauri seems to understand the deeper emotions that Sparx keeps hidden behind his comedy and blustering. Their relationship's best exemplified in the episode Evil Ages where Antauri and Sparx teleported to a Wild West time of Shuggazoom, Antauri's in the role of sheriff with Sparx as his deputy, summing up their roles with one another.
Nova: Sparx and Nova's relationship is one of the most complicated and discussed relationship on the show. Sparx loves to needle Nova to the point of anger, often getting himself punched in the process; however, despite this, it is clear that the two are very close friends, often competitive and teasing. As the series progresses, it becomes clear that Sparx harbors feelings for Nova deeper than mere friendship, and fans of the Spova relationship keep on being taunted with several near confessions of his secret feelings. It's not until Sparx' possession at the end of season four that Nova seems to return his feelings, pulling him from his possession by sobbing her love for him, and later, kissing him on the cheek, suggesting that she feels the same deep feelings for him. Unfortunately, the show's cancellation prevented a fifth season, and never will able to confirm what would have happened after the startling confession. Most fans, however, take Nova's confession as evidence that the romantic relationship was to become canon.
Gibson: Sparx and Gibson clash, both in the Robot and during battles, constantly arguing over the slightest of details (a classic Red Oni, Blue Oni friendship). Sparx loves to rile Gibson up (much in the same manner as Nova) and enjoys teasing him, calling him nicknames such as "Brainstrain" and Gibson often gives it right back, taunting Sparx' intelligence. Yet, despite their arguing, the two are as close as brothers, defending and sticking up for each other when necessary.
Otto: Otto and Sparx share a close and great relationship, often taking time out of other, more important duties, to hang out and play video games, or goof off, often getting into trouble together. Occasionally, the two drag Chiro, or even Gibson into their schemes.
- In Night of Fear, Sparx is afraid of losing his eyesight and thus being unable to fly anymore. Beforehand, he also shared a wariness of the ocean with Chiro.
- Unlike the other monkeys, Sparx occasionally refers to himself by his model designation, SPRX-77