Catra is one of the main characters in She-Ra and the Princesses of Power. She is the deuteragonist and a former antagonist. Starting out as a cadet in the Horde, Catra was soon promoted to the rank of Force Captain and eventually served as Hordak's second in command. After the invasion of the Galactic Horde, Catra briefly served as an agent of Horde Prime. After her reform, she became Adora's girlfriend.
She has one of the most pleasing arcs in character, next to Zuko of Avatar: The Last Airbender.
She starts off as a fun-loving girl who feels hurt when Adora leaves the Horde, which is actually a very believable reaction to someone who's best friend since childhood suddenly decided to leave them (though Adora's reasons for leaving the Horde were completely understandable as well, and she even tried to convince Catra to come with her to the Rebellion).
And speaking of her abandonment issues, even through all of that, Catra still does care about Adora and is reluctant to hurt her even if she refuses to say that she still sees Adora as her best friend (at least, until season 3).
One of her biggest weaknesses is probably Adora, and this comes into fruition in the last season of the show. Catra confesses that she loves Adora and they kiss, officially making their relationship canon. Almost everything she does comes from the anger that she feels for Adora leaving her to join the rebellion, and once she joins them, her motivation to be good partly comes from her love for Adora.
Her character design is much better than her 1980s counterpart, as it's much more detailed, creative, and a much better design for a cat girl like her.
In season 5, while she struggles with the fact that Adora is the strongest of all of them and the only one who could save Etheria by potentially sacrificing herself and leaves because she can't handle it, she joins the Rebellion and works her way to redeeming herself after getting chipped by Horde Prime, becoming Adora's girlfriend by the end of season 5.
Speaking of her redemption, when she and Glimmer were trapped on Horde Prime's ship, she uses her advantage as a villain who has Horde Prime's trust to help Glimmer escape. After this, Catra gets chipped and the others return the favor by saving her.
Incredibly dialogue catchphrase, like "Hey, Adora!"
She often acted abusive towards Adora after the latter left the Horde up until the former's redemption.
In season 3, she tried to destroy reality, and herself, just to one-up Adora.
Over the course of the series, she grows dark and bitter and makes her way up to the top of the Horde by hurting others, such as Scorpia, Entrapta, and even Hordak himself.
As satisfying as her redemption is, it also felt like a half-baked one, due to all the bad things Catra did, and how swiftly her redemption arc took place.
She was voiced by A.J. Michalka in Steven Universe.