The beginning of the Star Trek fic Safe and Sound has the young Lucille Harewood confronted by two boys who accuse her of being a terrorist like her father - and proceed to beat her up for it. If she hadn't had Khan's blood in her, she would've been seriously injured.
From the Gensokyo 20XX series, we have Yume Ni "Yu" Yakumo and it is to such a degree that the other kids prefer Reimu over her, especially, when she hits them. Apparently, she seems to have a Lack of Empathy, seeing as she tried to throw Reimu (attached to an IV) over a railing, the which of could have either killed or injured her, along with a nonchalant to eager tone about the other kids being her bitch.
Ojamajo Doremi: Rise of the Shadows: The Shadow Ojamajos are the same age as their counterparts (read: ages 11-12 for the older girls, 8-9 for the Tagalong Kid, and 2-3-going-on-11-12 for their final member), but they show definite instances of malice. These instances include insulting their counterparts from behind their backs, outright attacking them when given permission, mocking them for expressing grief, and finally killing them in cold blood.
In Reinforced Magic Harry's cousin Dudley and his gang of bullies actually throw acid at Harry because Dudley wants to see if they can make him look like the half-rotting version of Hel depicted in the school's Norse mythology display.
In The Consort Tournament some neighborhood boys once held Harry down while the rest of the gang killed the family Kneazle for being "too ugly to live." This marked the start of his belief that animals are better than people.
In No Competition Prudence Charnel left Hogwarts because some seventh-year students threw her over a railing and she would've died if one of the staircases hadn't moved. Mocking her appearance because of her being a hag didn't exactly help either.
In If I Only Had A Heart, Izuku is frequently bullied and mocked by his peers not only for being Quirkless, but for legally being a cripple with his damaged spine and missing arm and eye. They constantly tell him that it's impossible for him to be a Hero and once stole his prosthetic arm from him just to see his reaction.