The Lion King is largely regarded as one of Disney's best films, for good reason. The movie is a classic that broke boundaries and set a high bar for future animated movies, with its adult themes and complex characters. One of the most important characters in the film is the ambitious and untrustworthy Scar, whose thirst for power sets the entire plot in motion. Scar's actions directly result in the death of his own brother Mufasa, as well as the banishment of Simba for several years.
The film itself doesn't go into a ton of detail on Scar's backstory, instead focusing on his current role as Simba's devious uncle. This works for The Lion King, and Scar is still remembered as one of the best animated villains of all time, but his origins actually were explained in supplementary materials for the film. In a tie-in book, it was revealed how Scar got his iconic injury, as well as what his name was before that event.
The 1994 book The Lion King: A Tale of Two Brothers explored the relationship between Mufasa and Scar when they were younger. It also revealed that Scar's real name is Taka, which can mean either "waste" or "desire" in Swahili. In the book, Taka displays a power-hungry streak even at a young age, striking a deal with the hyenas and engineering several situations in which Mufasa could be injured or embarrassed. However, Taka's plans backfire when he is injured by a water buffalo and ends up receiving his signature scar.
Scar's birth name being Taka seems to have been a self-fulfilling prophecy. With a name like "waste," which many also interpret as "garbage," it seems that Taka's parents were setting him up for a tough life, but he instead leaned into the other meaning for his name, "desire." After his injury, Taka embraced his desire to become the king of the Pride Lands, and it became his sole motivation for the rest of his life. He adopted the name "Scar" so that he would never forget his biggest mistake.
One thing that makes Scar stand out from other Disney antagonists is the fact that he is the first one to be related by blood to the protagonist. He shows a willingness to kill his family members throughout the film, proving that the only thing that keeps him going is his jealousy and his desire to be king. This characterization is similar to the character of Claudius from William Shakespeare's Hamlet, which partially inspired The Lion King. Scar hits a lot of similar character beats to Claudius, including murdering his brother and acting through minions that later betray him.
Unfortunately, the more recent animated series The Lion Guard ended up contradicting Scar's original name and backstory as told in A Tale of Two Brothers. The show established that his birth name is Askari, the origin of his scar is from a cobra and he received his nickname of Scar by being belittled by Mufasa. This is a shame, as Scar's original name of Taka had such a clever double meaning. The fact that he chose to call himself Scar as a reminder of his past failures proves just how motivated he is, and shows that he has learned from his past mistakes.