Kaz and Oliver have been best friends since kindergarten, each of them has the other's back and their friendship always comes first. While Kaz is the “accelerator,” Oliver is the “brake.” He's a bit superstitious and cautious, but will take risks when needed.
Oliver is smart guy who always thinks before he does anything that may be dangerous. Unlike Kaz, Oliver will give things second thoughts, and is more worried. When Oliver started working at Mighty Med he instantly impressed Horace which landed him a job. He and Kaz come in a package since they're best friends and Oliver also made Horace give Kaz a job. Oliver is more responsible than Kaz and happens to usually get him out of trouble and sometimes gets mad when Kaz 'kazzes around'. Sometimes Oliver is forced into doing things by Kaz in the past but sometimes can also be given good advice by him at times.
Oliver's favorite superhero is Skylar Storm and is also his crush. In the pilot episode, Oliver says that he wish that she could see how big his heart is and was embarrassed when Kaz told Skylar that he was apparently making out with the cardboard cutout of her.
In I, Normo, Oliver does not like the way that Kaz was treating Skylar. He seems more protective about Skylar than Kaz and panics that he didn't look after her and says that he's a terrible friend. He then feels better after Skylar kisses him. When Oliver sees danger he snaps into action which is why he saved Stefanie's dog. He can sometimes annoy Kaz when he gets what Kaz wants and what Oliver doesn't really care about. He also enjoys playing pranks, just like Kaz.
Kaz (Best Friend)
Kaz and Oliver are best friends and are always together. Kaz, however, sometimes gets them into trouble and Oliver gets mad at him for it. in Pranks for Nothing they said they love each other, and Kaz said that Oliver is the best friend he could ever have.
Skylar Storm (Comic Book Hero, Crush and Friend)
Skylar is Oliver's all time favorite comic book hero and he has a crush on her.
Alan Diaz (Acquaintance and one sided Enemy)
Alan tries to get Kaz and Oliver fired.
Jordan is Oliver's friend who also likes comic books.
Gus is Oliver's friend who Oliver sometimes feels sorry for.
- Oliver has burgeoning medical skills.
- His favorite comic book superhero is Skylar Storm.
- When Kaz messes things up for him he uses the words 'kaz' and 'kazzing'.
- He takes commemorative fake photos with his best friend, Kaz.
- He has ridden on top of a skateboard.
- He has played ice football on a frozen lake but fell in and had to be evacuated to the hospital.
- Oliver has been in a helicopter before.
- His dad is a brain trauma researcher.
- Once Oliver came home with half of his head shaved.
- He likes to put Kaz's painful and embarrassing moments on video.
- Although shorter he is apparently the tougher of the two, as he was able to quickly overpower Kaz (I, Normo).
- He has been Stefanie's next door neighbor since he was three.
- He once saved Stefanie's dog.
- He hates it when Kaz scares him by saying boo.
- Stefanie once bought Oliver the same clothes that she bought her dog.
- He was once part of a band with Stefanie and was a back up back up singer.
- He is three days older than Kaz.
- He's really bad with nicknames.
- He pranked his mom by coming out sideways.
- He's a big fan of The Great Defender.
- He thinks whoever came up with exclamation points is a genius.