Suzano, from the Jackie Chan Adventures and Teen Titans fanfic A Shadow Of The Titans(and possibly the author's other story, Jewel Of Darkness, as a character with the same name and powers appears there as well), is unnecessarily rude towards everyone. At first his hatred towards Jade seems to be pure Fantastic Racism towards her part Oni nature, as he is part Japanese god, but as he is later shown on a team with what appears to be a demon and a ghost, it seems more likely he just uses Fantastic Racism as an excuse to let out his Jerkass tendencies.
Gizmo, Commander Hollywood (a HIVE teacher), and Kitten also apply.
In the Katawa Shoujo fic Lilly Epilogue: Family Matters, Lilly's father is this, even apart from the canonical Parental Abandonment inflicted on Lilly and Akira for six years. He is incredibly condescending to Hisao and Hanako, referring to them impersonally and making fun of their disabilities. In Hanako's case, he mocks her timidity and asks if she got her burn scars from catching the oven on fire; considering he was warned in advance and the real reason she got them, this is a borderline Moral Event Horizon. He does apologize to Lilly and accept Hisao in the end, though.
In the Saki doujin Captain Half'', Mihoko splits into two people in an attempt to cook for 80 people. Her counterpart is extremely mean, verbally and even physically abusing her teammates. When the coach barges in and complains about the other Mihoko "copying" her, the other Mihoko gives the coach a Death Glare that stops her in her tracks.
The Prayer Warriors are by and large not nice people, especially since they're willing to kill anyone who refuses to convert or who engages in behavior they disapprove of, including former friends. However, among them, Michael stands out, since he's fairly rude and short-tempered compared to the others.
Michael: (after Ebony asks to baptize Hermione) "I will do it women. Do not try and disturb a sacred ritual. I do not want you to ruin it." (Baptizes Hermione) "No go. I don't think you deserve it. I think you are lying. But because Ebony trusts you, I will give you another chance. Now go satanic bitch."
In Mega Man Defender Of The Human Race, Miss T is the most coldhearted of the Conduit's associates, and antagonizes Tiesel frequently. She also threatens to kill her other teammates should they make mistakes.
Harald, captain of the guard, has two of his men dismissed over how they treated Hans, and retaliates by beating him up.
Harken has, on at least one occasion, whipped a man so severely he died from it soon afterward. He also plans on whipping Hans, his brother with a cat of nine tails that has shards of glass in it, and is largely motivated by a desire to save face.
Hugo is quite lecherous and dismissive of Hans. He and the two aforementioned brothers were said to take part in the game of pretending Hans was invisible, and it's mentioned that, for that reason, "if Hans had been more specific with Princess Anna, he'd have told her how much he hated Hugo".