He has orange hair, sky blue eyes and appears to be a little chubby. He wears a white shirt with a green bow tie, olive pants, and brown boots. In "Money Broom Wizard" he has a yellow shirt, brown pants and brown shoes.
As far as his looks would suggest, Breehn has a high intellect amongst the few students in Ms. Baker's class. It is shown that he is way above average in his intelligence, scoring high rankings on tests and takes within great pride for this gift as shown in "Average Jeff". He also keeps himself well grounded at often times and acts much a like babysitter to Clarence and company when he is apart of their adventures. He tends to worry about things when they get bad like messes or when someone gets hurt, showing he is very cautious, as shown in "Dinner Party" where he's seen panicking after Clarence hurts himself from grabbing the insulation. He's also shown to be generally careful when doing things such as when he was performing a science experiment in "Honk". This behavior is likely the result of his family's meticulous and persnickety lifestyle and his parents' strict sense of discipline towards him. This is demonstrated when he constantly tells Clarence and the others to be careful or else his parents will ground him or when his mom is seen giving him a cold glare when Clarence asks about going to the attic which wasn't allowed.
However, for as nervous and submissive as Breehn comes off as, he has been shown to have a rebellious side to his character. In the episode "Zoo", Breehn's peanut allergy forces the class to skip a lot of the exhibits in the Zoo which frustrates them. So later when the class has lunch, to show his mettle, Breehn voluntarily accepts a peanut butter sandwich from Percy (who didn't know that peanut butter is made from actual peanuts) and when Percy tells Ms. Baker he did this, he quickly eats and swallows it despite Ms. Baker telling him to spit out and refused. It should be noted though that when his allegies kick in later and he ends up being taken away in by an ambulance, he shows clear regret, saying that "It wasn't worth it.". Also in "Puddle Eyes" Belson pretends he is away and Breehn says "What? I'm right here!"
- Blaide - Blaide and Breehn had been together in school since the first few episodes. It's unknown what kind friendship they have.
- Jeff - Breehn has a good friendship with Jeff. They're both very much the same as they're the most intelligent kids in their class and keep their things well organized. Breehn invited Jeff to his house in Dinner Party as one of his guests. In Breehn Ho, Jeff invited Breehn to his place on game night. So far in Season 2, Breehn and Jeff have been hanging out and talking to each other in Time Crimes and Field Trippin'. According to The Clarence Book of Friends, Jeff is said to be Breehn's "Secret Best Friend".
- Chelsea - Breehn is also friends with Chelsea.
- His name was originally Preehn.
- He has 9 buddy stars as seen in "Clarence's Millions".
- Like Clarence, Jeff, and Belson, Breehn is the only child in his family.
- "Dinner Party" is the first episode that has Breehn as a major character.
- The buddy star chart accidentally removes the H from his name.
- As shown in "Zoo", it is revealed he is allergic to peanuts.
- He had a pink backpack as seen in "Clarence's Millions". It's unknown if it was a color error, or if he's feminine like Jeff. However, this possibility is extremely unlikely. In Average Jeff, he now has a light blue backpack.
- He is one of the only characters to appear in the "Pilot" to not have a major change in appearance at all in the show. The minor difference is that his arms are not as long.
- In "Money Broom Wizard", he is shown in a yellow shirt. It is unknown if it was a mistake or if it was his original shirt before it was changed back to the shirt worn in the "Pilot".
- Blaide was (prior to Breehn Ho!) Breehn's best friend, but it is unknown why Blaide wasn't invited to Breehn's house.
- It is unknown why Breehn sometimes poses his arms the way Gilben does.
- There's an error in Game Show where his eyes are black instead of blue.