Brains: Evil; Brawn: Good: In his conflict with Scar. Though it's shown in the sequel that, while not perfect, he manages to turn the Pridelands around and is a far more competent ruler than Scar, who had no idea what to do with his power.
Heroic Second Wind: Scar nearly backs him off of Pride Rock while he's trying to guilt-trip him. But just as he's about to push him off to his death, he admits to being the one who killed Mufasa. Needless to say, Simba pounces on him in a instant and starts choking him to get him to admit the truth.
Elaborating on that, Scar never had a queen, despite being surrounded by lionesses. Also, it's easy to forget, but Simba and Nala had an Arranged Marriage, which implies that Scar didn't just fail to get a queen, but refused to get one.
Though we do find out he had a mate in the sequel and not having an Arranged Marriagemight be justified by the fact that he's not first in line.
Busted! In a deleted scene found on the Diamond Edition Blu-Ray, Scar discusses his need to find a queen and then attempts to push Nala into becoming just that. Needless to say, she angrily refuses and runs off. The scene would be the set-up for the scene where she finds Simba, but it was cut because it featured really creepy undertones (obviously), according to the commentary.
The above mentioned scene is included in the musical during "The Madness of King Scar."
It bears mentioning that, in said deleted scene, Scar doesn't seek a queen because he's attracted to any of the lionesses. He's after the extra status boost that comes with having one and especially the heirs, and all but says this to Nala herself.
Bad Boss: Lets the hyenas run rampant over the Pridelands until even they run out of food, casually manipulates all of them into helping his selfish scheme and ultimately tries to pass the blame onto them when he tries to weasel his way out of justice.
Berserk Button: Mentioning how much better of a king Mufasa was than him, probably because he knows it's true. Just using the M-word in front of him by itself sends him into a rage.
Bigger Bad: Of the sequel, since the primary villains there are his sympathizers wanting revenge. In 1 1/2 as well, where the main conflict is essentially the same of the first movie, but because they're telling from Timon and Pumbaa's point of view, the primary villains are the Hyenas, and Scar's machinations serve only as the background.
Simba: Uncle Scar, when I'm king, what will that make you?
Scar: A monkey's uncle.
Despotism Justifies the Means: Quite happy to let the Pridelands go to hell in a handbasket if that means he can be King. He's also pretty upfront that he wants the job for the power and refuses to even acknowledge that he's supposed to have duties and responsibilities to go with them.
Evil Sounds Deep: Scar carries a subtle reverb in his voice that becomes noticeable whenever he is dripping with sickly-sweet sarcasm or completely loses control of his temper. Of course, his voice is considerably less deep than Mufasa's...
Fisher King: Scar turns Mufasa's lush and green Ghibli Savanna into barren, dry, dead Mordor. Justified in that he allowed Hyenas into said lands, who over-hunted with the lions restrained by Scar from keeping them in check, though this does not account for the drought. Possibly Simba's return coincided with the rainy season.
Genre Blind: He sends his bumbling minions to kill someone whom they've already failed to kill, and just look at the results of the aforementioned Evil Gloating.
Good Is Dumb: Averted. Scar is no smarter than his brother, yet is resentful that Mufasa gets to be King instead of him. When he finally does become King, it becomes clear he is not as smart as his brother; Scar is a lazy hedonist who isn't even interested in maintaining the Pridelands.
Green-Eyed Monster: Several lines in "Be Prepared" imply how jealous he is of Mufasa's success as king and the "injustice" that he's no longer next in line for the throne after Simba's birth. Heavy emphasis on the "monster" part. He's a literal example as well, since he really does have Green Eyes. Also notice that, in Real Life, lions don't have green eyes, making the use even more metaphorical.
A Handful for an Eye: During the final battle between himself and Simba, Scar kicks it off by throwing burning embers into Simba's eyes.
Manipulative Bastard: One of the classic movie examples and fitting for a villain in a Shakespearean-style film. There are very few characters in the story whom he does not deceive, and he sometimes manipulates others purely for his own amusement.
Psychopathic Manchild: Best exemplified by his "I am the King, I can do whatever I want" excuse, because it is essentially the attitude of Simba as a cub, even though Simba never meant it in such a bastardly way.
Pyrrhic Victory: His original fate in the Alternate Ending. He wins the fight with Simba by throwing him off Pride Rock, but is then burned to death himself when the fires surrounding Pride Rock engulf it. By throwing Simba off Pride Rock, he actually saves Simba from suffering that fate and allowing him to have his happy ending anyway, making Scar's victory in the fight meaningless.
His plan turns out this way. He succeeds in becoming King, but the once-bountiful Pridelands quickly go to hell in a handbasket under his disastrous and self-serving leadership. Even the hyenas think that Mufasa's reign was better for them.
Red Right Hand: His scar, and his claws that are always bared (unlike the others).
Sanity Slippage: More obvious in the musical, but still visible in the movie. The musical has a number called "The Madness of King Scar," where he begins to go completely insane.
Sanity Slippage Song: "The Madness Of King Scar" in the musical version. He grows more insane as the song goes on, eventually seeing the ghost of Mufasa everywhere and becoming desperate to have cubs to continue his line. He also becomes increasingly paranoid, believing that the lionesses hate him (which they probably do) and are plotting to murder him.
Smug Snake: After becoming king. Although Scar was a master of manipulating everyone around him to seize the power he craved, he proved to be utterly incompetent at actually using the power once he had it, though this was more due to laziness and selfishness than a lack of intelligence. He hadn't been raised to be a king so he had no experience. Like Simba as a cub, he thought that it was just all about the power and the glory rather than actual hard work. He'd originally persuaded the hyenas to support him by promising that they'd never go hungry again, but the drought in the Pride Lands leads to a famine and causes the hyenas to begin grumbling about Scar even before Simba comes back.
The original ending of the film had a far more pronounced one. After his fight with Simba, which ends with Simba being the one thrown off Pride Rock (but lives), Scar is last seen laughing insanely as the fires surrounding Pride Rock engulf and kill him.
Villain Song: "Be Prepared" were he explains to the Hyenas how he intended to murder his brother and nephew to become king. There is also a cut reprise to "Be Prepared" were he introduces the Hyenas as his 'executive staff.'
Wanting Is Better Than Having: After killing Mufasa and finally becoming the King of Pride Rock, he ends up turning the paradise to ruins. Scar is obviously too proud to admit that he wasn't cut out for the job.
Wicked Cultured: Not only his speech is the more refined in the movie, but somehow he knows about the gene pool.
Psychopathic Manchild: While their not as immature as Timon and Pumbaa, their behavior can get childish at times, such as the infamous "No King! No King! La! La! La! La!", bit. Typically, they come off as mischievous teens, particularly in the series.
What Happened to the Mouse?: In the sequel, they only get a passing mention that they and the rest of the hyenas left the elephant graveyard shortly after the events of the first movie, and after the battle they don't appear in the third at all.
They appeared from time to time in the TV series.
"And if I see any strangers, don't talk to them. Come straight home. Okay, okay. Can I go now? Please?"
Rage Against the Reflection: During "Not One Of Us", as he's being driven from the Pride Lands, he looks at his reflection in the river. While Simba once saw Mufasa in a pool of water, all Kovu sees is Scar, which leads to this.
The Chessmaster: Despite being Ax-Crazy, she shows some apsects of this. She trained Kovu from his adoption to sneak into the Pride Lands and become her instrument of Simba's destruction. Then she proceeds to use this to throw Simba off his game by revealing it to him (even though Kovu already underwent a Heel-Face Turn by the time).
The Dark Side Will Make You Forget: Its implied by how she reacts to Nuka's death that she did genuinely love her kids (and Scar, considering he's the one the revenge plot is for), but is so consumed by her thirst for revenge she's lost sight of that.
Fatal Flaw: Her thirst for vengeance. While she shows at Nuka's death and other times that she loves her children, her all-consuming thirst for vengeance causes her to be an Abusive Parent, ultimately causing the death of one of her children and the Heel-Face Turn of the other two, as well as her own demise.
The Sociopath: While Scar, being more calculating and subtle, would qualify more as a psychopath, her harsh attitude and aggressiveness make her this. Her Villain Song is not subtle about her being this.
Villainous Breakdown: Naturally she was never the most sane person, but after Nuka dies, she throws her Evil Plan out the window, banishes her adopted son, and starts a full-out war with the Pride Lands. Gets even worse when Kovu and Kiara return and stop the fighting, threatening her own daughter with death.