The Incredible Hulk has always been one of the most powerful entities in the Marvel Universe. Although the green version of the powerful occasional Avenger is the most popular, there is an entire color spectrum of Hulk characters that rival the original. Marvel Studios has already brought the Hulk's menacing power to the Marvel Cinematic Universe, and She-Hulk is set to star in her own series on Disney+. However, one of Marvel's most recognizable Hulks, the Red Hulk, still hasn't jumped into the MCU yet.
The main Red Hulk's alter-ego is Gen. Thaddeus "Thunderbolt" Ross, whose presence in the MCU has already been established. Traditionally, Thunderbolt Ross is mostly known as an enemy of the Hulk, hunting down Bruce Banner because he wanted to protect his daughter from the Hulk's rage. But in Jeph Loeb and Ed McGuinness' Hulk #1 in 2009, Ross eventually grew jealous of the Hulk's power and found a way to steal Banner's power to transform himself into the mysterious Red Hulk.
The Red Hulk's identity was kept secret for a long time thanks to the help of M.O.D.O.K. and the Intelligencia. They installed a perfect body double for Thunderbolt Ross so that nobody could link his disappearances to the Red Hulk's missions around the world.
This Hulk possesses all of the strength and speed of Banner's version of the monster. He also has the ability to absorb and emit gamma radiation, which makes him an absolute nightmare in any hand-to-hand combat situation. Ross has one more skill that Banner rarely got a handle on, the ability to transform into his Hulk form and back to his human form at will.
If Red Hulk does enter the MCU at some point, this will instantly change the power dynamic. This Hulk might just be the most powerful Hulk in the MCU, especially considering the fact that Bruce Banner has taken his Professor Hulk form. Banner may not be able to keep up with the raw radiation-emitting strength and speed of the Red Hulk.
Even beyond Thunderbolt Ross, there are a few other Red Hulks who are primed to join the MCU too. Ross's daughter, Betty, briefly turned into the Red She-Hulk, and she's already part of the MCU too.
Outside of the Ross family, General Robert Maverick joined the U.S.Avengers as a mustache-sporting Red Hulk in 2017. Using modified S.H.I.E.L.D. technology, Maverick changed himself into the Red Hulk, who had power in limited bursts. While he has the power of the Red Hulk, the details of his transformation could add some intriguing wrinkles to the traditional Red Hulk story, and his relatively scant history means that he could be more of a blank slate within the MCU itself.
With She-Hulk set to debut soon, the MCU Hulk's lore and mythology is set to grow more than it has in years. And whether he debuts there or in a later phase, it's almost certainly only a matter of time until one of Marvel's Red Hulks debuts in the MCU.