Robotboy was intended by Professor Moshimo to resemble a real boy. He has a round head with blue 'ears'. Most of his body is white, but his hands and feet are blue. He also has luminous, light blue eyes. His eyes turn red when he changes into his super activation mode.
In deactivation mode he is small and resembles a doll. His ears are folded away so only his round head is mainly visible. His eyes are also closed and they remain light blue.
In super activation mode, he is much taller and has long legs. He has a medium-sized, primarily silver instead of white body. His ears, hands, and feet are dark blue. He has a dark blue mask-like face with a red outlining.
Robotboy is very naive almost to a fault, and is very easily led (most often by Gus, and into certain negative situations). However, when things come down to the wire, he's often the first to react and has a fair understanding of his surroundings and circumstances.
Robotboy is overprotective of Tommy and his friends (and Robotgirl during their brief encounter) On more than one occasion, he's been openly willing to do anything to keep each of them safe. If Tommy orders him to stop though, Robotboy will stop almost instantly. Robotboy's over-protectiveness is more blatant in the beginning episodes of the first season, then again near the end of the season. This cycles throughout the first three seasons that were aired.
He is shown not to like dishonesty, and has a fair bit of respect for those around him (except for Gus). He appears to like having fun with Tommy and on occasion Lola.
- Robotboy is similar to Jenny Wakeman and Robot Jones. He is also similar to Pinocchio as Pinocchio, Robotboy and the previous two robot characters mentioned all want to be treated as real life human beings. They all share human-like characteristics.
- Robotboy, like Jenny, could also be inspired by Astro Boy.
- Robotboy acts much more serious in his super activation form.
- In the French dub Robotboy talks whilst in super activation mode. However when he is in this form in the English dub he remains silent.
- It is unknown what happened to him after the series was cancelled, but it could implied he still fights the villains and saves the day.