Cody Jenson: Raped Madeline Shiohara and bit out her neck. How did he feel? He didn't.
Danya: Establishing Character Moment in the first version was when he was briefing the v1 students with a very... smug tone. Then towards the end mentioned he hated punks, and ordered his minions to kill a student for wearing his hat sideways.
Jeremy Franco kicking Kimberly Nguyen in her bullet wound for refusing to give him her fedora, then taking it anyway.
In the video The Unspeakable Deeds of Bill 42, it's not enough for the character representing the bill to fine people for meeting to air their grievances. He has to up the evil quotient by deliberately knocking over a woman's crutches.
Seto Kaiba also gets a bit of a gem. In episode 19, Mokuba says "Big brother, whenever you smile, a puppy dies." When Mega Ultra Chicken is summoned, Kaiba smiles, giving the caption "+1 DEAD PUPPIES." It continues, all the way up to "+9001 DEAD PUPPIES."
The Ascended Meme NEDM (Not Even Doom Music) came from a literal example of this. Except, replace "kick" with "burn," and "dog" with "cat." Anonymous was not pleased.
Awkward. has a fight between Lester and Alex culminate in Alex telling Lester to give up on his relationship with Steph because "everybody knows you're just going to mess it up like last time". Lester doesn't take it well. Later we find out that Ernie dumped Karen, calling her "worthless".
Something Awful's Awful Movie Database has "The Terrible Truth About Dolphins," allegedly a "documentary" but mostly concerned with the director's overwhelming hatred for dolphins, who are abused throughout the movie.
Welcome to Night Vale gets this with Strex giving Cecil a birthday present. It attacks Khoshekh and leaves him hospitalized. Strex didn't understand why it didn't work out.
RWBY: Pretty much everything Cardin says or does. Special mention needs to go to his racism against Faunus: in one scene, he's shown tugging on Velvet's rabbit ears and laughing at her before turning to his goons and saying "told ya they were real, what a freak". In a later scene in history class, he tries to explain Faunus military victories against humanity with "it's easier to train an animal than a human" - with poor Velvet and Team RWBY's Blake Belladonna being present, too.
Yang's mother, Raven Branwen, partakes in this when she leaves a message for Yang - notably, through Qrow and not told to Yang herself - that saving her life from Neopolitan was a one-off "kindness" that Yang shouldn't expect again. If Yang gets in that kind of nasty situation again, she's on her own.
It comes across that Mercury let Ruby get out into the stands area just in time to see Penny be killed. That smile he has as she drops to her knees in tears.
General Ryde in Engines of Creation kills one of his own men by crushing his skull with his boot for being so stupid as to get injured.
In the webseries and novel versions of Noob, one of Roxana's earliest story-relevant moves was to kill Sparadrap's entire pet collection.
Mannequin and Burnscar getting revenge on Skitter by attacking her territory and brutally killing dozens of civilians, with Mannequin making a point to murder parents in front of their kids.
Attacking Parian's territory and killing nearly everyone there, including Parian's family, before mutilating the survivors to look like them so that they can serve as decoys to draw the fire of local Neo-Nazis. To top it off, one of the Nine members the victims were altered to look like was the Siberian, who literally cannot be harmed by anything, so the motivation was sadism as much as tactics.
Attacking a hospital and starting with the nursery. It also bears mentioning that the hospital was in a rural area and served multiple counties, so it was both very crowded and too far for anyone but the police to intervene, and it's implied that the Nine picked this target specifically to ensure that the chances of escape or rescue were virtually zero.
Attacking a ski resort and gruesomely killing nearly three hundred of its residents before kidnapping 999 more and stashing them away, promising to kill them if anyone but Theo tries to stop them.
Bonesaw kidnapping Blasto, using him to clone the Nine, and then forcing him to sing a children's song for four solid months before he drops dead from a stress-induced stroke.