As his name suggests, he's a living skeleton, so he doesn't have skin nor organs. A purple gemstone is embedded in his chest, which may be the source of his life and powers. When he's suffering a strong feeling, he's surrounded by a purple flame. Inside his eyes' sockets are purple pupils.
He wears a red cape, gray shoulder pads, and also wears a pair of maroon gloves and boots.
He seems to be straight forward and honest when talking to others, and is capable of being open with them sometimes even if he is sometimes defensive. He gets easily aggravated when annoyed which makes him unable to focus on tasks.
He hates everything about the frame store he works at, besides the company of his best friend Brandon who also works there. Even though he hates his job, he also tries to do a good job at it and is usually very responsible, though it seems that he's just a responsible person in general.
Despite the occasional acts of rudeness or selfishness, he seems to have at least some kind of morality, ethics or principles. Due to this sense of right and wrong he has, it's easy to assume that he is at least usually well-intentioned in his actions.
It is confirmed that he is jealous of the cool adventures K.O., Rad and Enid get to go on all the time, which makes sense considering how boring his job is. He has no talent with magic, but he’s taking night courses at the community college in hopes of getting better.
Abilities and Powers
ARMS has magical powers; he can magically create fire and blue electricity with his hands. But he hasn't had a complete control of it yet, although he said he's taking night courses to dominate it.
- Skull Toss: He can throw his head at a target, and it's pretty strong, but then he has to go pick it back up and it's kind of embarrassing.
- Reassemble: He can draw any of his detached bones back to his body wherever his head is located, and can magically reassemble himself.
- "Lakewood Plaza Turbo"
- "Let's Be Heroes"
- "Let's Be Friends"
- "You're Everybody's Sidekick"
- "Jethro's All Yours"
- "You're Level 100!"
- "I Am Dendy"
- "You Are Rad"
- "Know Your Mom"
- "Everybody Likes Rad?"
- "You Have to Care"
- "Plaza Prom"
- "The Power Is Yours!"
- "We Got Hacked"
- "Let's Watch the Pilot" (pilot)
- "RMS & Brandon's First Episode"
- "Plaza Shorts 1"
- The purple fire that emerges from him and floating head could be a reference to Lewis from Mystery Skulls.