Frozen: Prince Hans, according to Word of God, had never been loved, and the way his father and his brothers, sans one, treated him was downright cruel. The only people who didn't mistreat him were his mother and one of his brothers, but they were unable to help him cope with life. The novelization clarifies he Used to Be a Sweet Kid who wanted to find happiness, but his issues slowly transformed him into a dour and cynical man bent on achieving fame and greatness no matter the cost. He's now trapped in the homeland he wanted to escape, unable to break free or seek redemption.
Evelyn Deavor from Incredibles 2. Her parents, who she describes as "sweet and trusting", and was shown as being very close to, are revealed to have been killed through a knock-on consequence to the illegalization of superheroes. Her father tries to call the supers for help when their home is broken into, but there is no answer and he's shot dead. Her mother dies of grief within a week of this death. This leads Evelyn to conclude that supers are not to be relied on and believes that regular humans are kept weak and expectant on their help. She wants supers to remain illegal as a result.
Tai Lung, the villain of Kung Fu Panda, Used to Be a Sweet Kid before his foster-father built up his Pride and ambition to unrealistic heights. When Master Oogway refused to entrust the Dragon Scroll to an Arrogant Kung-Fu Guy, his sense of entitlement and lack of self worth drove him to criminal violence. Emphasized at the climax of the film, when he repudiates Shifu's apology and can't accept the 'lesson' of the Scroll because he saw the scroll as the only thing that mattered and could not see the value within himself.
Lord Shen from Kung Fu Panda 2. Neglected by his parents due to his poor health, Shen strove to make them proud but started down a dark path in his pursuit. When he heard a prophecy foretelling his defeat if he would not change his ways, Shen killed anyone that matched the description, thinking that averting his fate would make his parents proud. When they instead banished him, Shen saw it as a final sign that they didn't love him and swore retribution. His plan to conquer all of China is essentially an attempt to get over his issues and find some measure of happiness and fulfillment. Shen himself even admits that it probably won't be enough but to stop now would make all of his actions pointless.
King Haggard from The Last Unicorn. He's an old man who epitomizes The Eeyore in temperament, which is precisely why he's imprisoned the unicorns.
King Haggard: I like to watch them. They fill me with joy. The first time I felt it, I thought I was going to die. I said to the Red Bull, "I must have them, all of them, all there are! For nothing makes me happy, but their shining and their grace." So the Red Bull caught them. Each time I see the unicorns, my unicorns, it is like that morning in the woods, and I am truly young, in spite of myself!
Legends of Oz: Dorothy's Return: The Jester was made into a mockery by his jealous sister, the Wicked Witch of the West, and now no one will take him seriously like they did with her. He wants to take over Oz to gain that respect. His Villain Song has quite a sad tone in the middle:
"I shall possess / my one happiness / The power I covet, and who wouldn't love it? / Would you? / Now would you dare try me / and would you deny me what's mine?"
The titular character in Megamind is an alien from another planet whose space pod crashed into a prison, where the prisoners found him as a baby and raised him behind bars (and convinced him to believe crime was good and cops were bad). He was ostracized by everyone around him because of how different he was (and his terrible attempts at winning people over didn't help much). On top of that, he was constantly overshadowed by Metro Man, whom everyone saw as a hero, so he resolved himself to becoming the best villain he could be. The movie itself is a case study of a character who's only a villain because the world around him convinced him that's all he could ever be.
Necross from Mune: Guardian of the Moon is played like a typical Satanic Archetype, having been banished to the Underworld for being greedy and ambitious for power, and manipulating people with snakelike spirits called Corruptors. But then it's revealed that he only turned evil because he was possessed by a Corruptor himself, and he may or may not have been in control of his actions the whole time. Once the Corruptor inside him is destroyed, Necross smiles warmly at Mune for saving him, and dies peacefully.
Tempest Shadow in My Little Pony: The Movie (2017). As revealed in her Villain Song "Open Up Your Eyes", she was attacked by an Ursa Minor as a filly, destroying her unicorn horn and scarring her face. Not only did this kill her dream of attending Celestia's School for Gifted Unicorns, her now violent and unstable magic alienated her from her friends. This caused her to lose faith in friendship, and she ran away from Equestria, growing up to become the ruthless and feared leader of the Storm King's army.
Puss in Boots (2011) has Humpty Dumpty, who was once Puss' closest friend and "brother" from the orphanage. He was never truly accepted by anyone around him (except for Puss and Imelda), knew full well he was different and had no idea who (or what) he really was. He had big dreams of finding the Golden Goose in the castle in the sky, partly because just one golden egg would make him rich for life, but he truly felt as though he belonged up there rather than where he was. He commits a number of petty crimes and schemes and eventually betrays his friend to further his plans but is clearly torn about the latter. By the end of the movie, he performs a Heroic Sacrifice to save Puss and his hometown and is revealed to have been a golden egg himself all along. He truly did belong up there after all.
Rise of the Guardians has Pitch Black, the Boogyman, who is unhappy because unlike other fairytale characters, children fear him instead of loving him.
Aeon the Terrible in Rudolph's Shiny New Year is a monstrous vulture who kidnaps Happy the Baby New Year and tries to stop the New Year coming, which is undeniably a villainous thing to do. But the true reason he’s doing that? Aeon (hence his name) will live until he is one eon (1 billion years) old, and then he will die by turning into ice and snow. And his eon will finally be up in a few days. He captured Happy because he is terrified of dying. Thankfully, Rudolph and Happy are able to avert this fate via Happy's huge ears making Aeon laugh, thus saving him by keeping him warm and alive.
Steven Universe: The Movie has Spinel, who was created for the purpose of being Pink Diamond's friend and playmate. Pink repaid her by convincing Spinel to stay behind in her space garden while she would go to Earth, though she promised that she would eventually return... but this never happened, leaving Spinel to wait alone for 6,000 years only to discover that Pink Diamond eventually died having completely forgotten about her. As such, she decides to destroy whatever happiness Steven has as revenge for her own happiness being taken away. This even feeds into her defeat as Steven doesn't so much succeed in talking her down as much as she talks herself down, breaking down crying while curb-stomping him and admitting that she's a Reluctant Psycho and that all she really wants is a friend who she can make laugh.
Teenage Mutant Ninja Turtles: Mutant Mayhem: Superfly, despite his personal antagonism by the present is still a tragic figure. The flashbacks of him as a baby fly mutant and his fond memories of his "father" Stockman, as well as fully internalizing his dreams of making a family with the other mutants make it clear that Superfly Used to Be a Sweet Kid. A clear Foil to Splinter as a mutant who became like a father to other mutants. However, the world of humans didn't leave a good impression on him. First, he lost his "father" Stockman to TCRI's attack, but he just ran away with his other mutant brothers. But eventually, like the Turtles, he saw all the good the human world could have and wanted to integrate with the human world alongside his family when they were old enough. They were violently rejected like the Turtles were, but to make matters worse, the relentless pursuit of one aggressor forced him to beat him down to an inch of his life. This convinced him that human and mutant integration was impossible and gave him a taste for violence against humans. Had he instead encountered someone more reasonable and understanding like April, there was a chance for him to join the Turtles' family at the end like the rest of his mutant brethren, rather than becoming outcast from them all thanks to his refusal to quit.
Stinky Pete from Toy Story 2. All of his actions are evil because for years, no child bought him, and he had to watch every other toy be sold.
Up has Charles Muntz. He was once a good and noble explorer whose passion for adventure inspired others, including the protagonist Carl. But then Muntz was wrongly accused of fabricating the skeleton of a giant bird he discovered in the lost world of Paradise Falls in South America. This accusation caused him to be publically cast out of the order of explorers. Humiliated, Muntz returned to Paradise Falls to capture a live specimen of the bird species he discovered to prove he wasn't a fraud... only for the mission to take seventy years instead of just a few months or years. By the time of the movie, the decades of failure and isolation have turned the now elderly Muntz into a bitter shadow of his former self, unable to let go of his past humiliation or move on from his outdated mission. When he realizes how far Muntz has fallen, Carl can't help but feel sympathy for him because he was once a hero. In the end, Muntz's obsession leads to his own death, and the worse thing is, even if he succeeded in his mission, it would've All for Nothing, because the age of explorers has long since passed, and most of, if not all the people who accused Muntz of fraud have died. Furthermore, South America is no longer the mysterious world it once was, meaning even if Muntz succeeded in bringing back the bird, his discovery would've been quickly overlooked.
