Elliot is like this naturally though he ruthlessly suppresses it, resulting in his notorious "wooden reserve", because he considers it a character flaw.
Elliot: Have I ignored non-violent solutions because I wanted a fight?
Ellen shares Elliot's excitability but exhibits less control over it.
Catalina is very excitable which is not surprising given that she's a redhead.
However she caught the zebra finch in the third test involved breaking its wings.
She deliberately misused the quartz shooters, explicitly powered down by design to prevent injury, to fire magic shots strong enough to crack tree bark.
When Rascal complained that she was refusing to shoot an easy target on account of a crush, she suplexed them with no hesitation.
Once the fourth test concluded, she was raring to confront a husk alone with no backup, no gems, and no plan.
The Guy in Tellurion gets riled up by the church guards easily, and has to be held back on occasion. Given the opportunity he'll pick a fight even if outnumbered and outgunned.
The eponymous Vattu, who has no respect for authority and can hold her own against a muscle-bound giant three times her height.
Alex from Weak Hero always fights with 100% guts and grit, and rarely thinks before throwing himself into battle. This was especially true before he suffered a beatdown from Jimmy, which tempered his fire a little (but not completely).
Alex Go, or more appropriately, Alex FuckOutMyWay...
her ability to mimic Kamina's epic stances over the smallest setbacks.