The Hidden Transformation of Smart Hulk: What If...? Season 2 Reveals Surprising Origins

The Untold Story of Smart Hulk

A huge piece of Bruce Banner's story as Smart Hulk in the MCU still hasn't been explored, but What If...? season 2 might have revealed some new information about his hidden transformation. Mark Ruffalo has portrayed super-scientist Bruce Banner since 2012's The Avengers, and has perhaps seen more changes than any other major superhero in the MCU's history. Edward Norton's previous iteration of the Hulk in 2008's The Incredible Hulk proved the creature to be uncontrollable, but the savage Hulk has since become an intelligent, controlled and balanced member of the Avengers known as Smart Hulk. This transformation took place entirely off-screen prior to the events of 2019's Avengers: Endgame.

Smart Hulk at a cafe in Avengers Endgame

During Bruce Banner's debut in the MCU's Phase 1, the gamma-irradiated genius was hellbent on finding a 'cure' for his Hulk infliction. This hunt brought him into contact with Mr. Blue, a.k.a. Dr. Samuel Sterns, Tim Blake Nelson's scientist who is returning as the Leader in Captain America: Brave New World. After learning that the Hulk couldn't be cured, Banner instead focused on taming the beast, which proved vital to the Avengers' success during the Battle of New York and the Battle of Sokovia. Now, however, Marvel Studios may have hinted at this hunt for a cure being a continued quest for Bruce Banner and other members of the Avengers.

What If...? Season 2 Reveals Iron Man's Efforts

Marvel Studios explored the Holidays during What If...? season 2, episode 3, 'What If... Happy Hogan Saved Christmas?' During the Christmas-themed episode, it was revealed that Tony Stark had been keeping a vial of Bruce Banner's gamma-irradiated blood safe in the Avengers Tower, and had been running tests on the blood in an effort to ease Banner's transformations. Stark's experiments on Banner's blood had already happened prior to the divergence point of What If...? season 2, episode 3, meaning these tests likely happened in the MCU's live-action continuity, too. Banner's blood played a key role in the series' Holiday episode, as Happy Hogan used it to transform into the Freak.

The Avengers in What If...? season 2 episode 3

Indeed, both Bruce Banner and Tony Stark knew that there was no clear-cut cure for the Hulk, but Stark still worked on Banner's blood to help his anger. If Banner could control his anger more naturally, the Hulk would be triggered far less, perhaps allowing the scientist to live a normal life. These experiments were perhaps hinted to work, as Bruce Banner neglected to transform into the Hulk during What If...? season 2, episode 3, even when all his fellow Avengers had been put in danger by Justin Hammer and his goons. These tests also inform a major piece of Bruce Banner's live-action MCU journey, particularly him becoming Smart Hulk.

The Avengers fighting Freak in What If...? season 2 episode 3

Iron Man's Hulk Experiments Explain Banner's Smart Hulk Decision

Bruce Banner and the Hulk's tumultuous relationship had always prompted the former to search for a cure, but Avengers: Endgame revealed that he had instead embraced his Hulk persona, allowing the pair to operate together as Smart Hulk. This transformation was suggested to be in response to the Hulk's impotence in Infinity War, but actually makes more sense as a result of Tony Stark's experiments in search of balance. Stark and Banner had worked together in their secret Mexico laboratory to combine the brains and the brawn, perhaps ending years of experiments on Banner's blood that What If...? season 2 has now confirmed were taking place.

Tony Stark in What If...? season 2 episode 3