Insufferable Genius: Claims to never make mistakes, and more prone to insulting/prodding at the less intelligent fighters on their dumber moments than his co-host.
Lack of Empathy: Often is incredulous at some fighter's backstory, especially if they do something that avoids gaining power.
Mad Scientist: He uses rats for genetic testing, dissected a "voluntary" Goomba to study its anatomy, and frequently states scientific real world facts on the combatants' tactics/weapons and how they can effectively kill a person.
This is revealed to be his overall look in the second Death Battle Q&A video.
Boomstick: *when discussing Link's hookshot* "Man, that really would of helped to get that last beer all those times... probably still be married."
Wizard: "Doubt it."
Also in the Batman vs. Spider-Man episode.
Boomstick: *when discussing Batmans' Utility Belt* "That belt has pretty much everything, grappling hook, explosives, beer... maybe not that last one, but mine would".
And also in He-Man vs. Lion-O,
Boomstick: *When discussing the Sword of Omens Tractor Beam* "...Which is perfect for when you're on the couch! swooooorrrd of omeeeeens, give me snacks beyond snacks...and a beer!"
All Men Are Perverts: If there's an attractive female on the show, you can bet your money he'll make a perverted comment at her expense. note So far, this counts all females in the show, except for his ex-wife, "tween pop star" Rebecca Black, Princesses Zelda and Peach, and Rainbow Dash (a pony).
Arch-Enemy: Pop-stars in general. He hates them even more than his "bloodsucking ex-wife". Considering how much he hates her, that says a lot.
Artificial Limbs: He has some kind of robotic left leg, according to the gag reels, it houses explosives.
Girl on Girl Is Hot: He certainly has no objections to how Rogue ended the fight between her and Wonder Woman.
Half-Human Hybrid: Possibly. The Ivy vs. Orchid video has him imply that his father was a zombie pirate.
Hidden Depths: Wiz comments in the Goku Vs. Superman fight that Boomstick's remark involving Superman's disguise was surprisingly profound. He's also surprised that Boomstick knew so much about dinosaurs when he discussed velociraptors.
The Watson: He tends to be the one to ask the questions about Wizard's scientific facts so that they can be more easily explained to the audience. According to many 'Behind The Scenes' videos, Boomstick tries to contradict Wiz's researching and claims with questions normal people would ask about the combatants.