This is She Hulk. Her name is Jennifer Walters, and she’s the cousin of Bruce Banner. She was created by Stan Lee and first appeared in 1980. She’s always been a unique character and not a “rebrand” of Bruce.
She got her powers when she needed an emergency blood transfusion and her cousin, Bruce Banner, was the only available donor. It gave her the powers of the Hulk (comics, right?), and she became the “Savage” She Hulk. Initially she was drawn and designed by John Buscema to be more of a “warrior woman” style, akin to what you would see in Conan the Barbarian.
In the late 80’s, she was used in The Avengers title, but John Byrne really took to the character and used her in both his Fantastic Four run and relaunched her second solo title. In the Sensational She Hulk title, she “broke the fourth wall” long before Deadpool was even created. She’s also had a few different looks over the years, but this is the one most know. She also had a good run with Dan Slott, and recently from Charles Soule
Every now and then (dating even back to the 80’s), whenever Jennifer would be overcome with rage, she would revert to a more “Hulk-like” appearance and character. In Civil War 2, she was “nearly killed” and suffered PTSD that kept her in this bigger “rage” + “maybe mentally dumb” state.
Even with the more “man-ish” appearance found in the recent Mariko Tamaki run, the character is in no way a “trans version” of Bruce (whatever that means), or a “gender swap”. While her new form has generated dislike, it’s a long-established version of the character. Jennifer’s character is nearly 40 years old, with hundreds of books.
Hope that helps. Check out my video below for a more in-depth discussion on this weird phenomenon, but really, what more needs to be said?