'What If..?' Mid-Credits Scene: Who's Inside The Hydra-Stomper?

'What If.. The Watcher broke his oath?', the final episode of What If's? first season, picks up right where the previous episode left off. Forced to break his oath and intervene when an Infinity Stone-wielding Ultron threatens the safety of the multiverse, The Watcher gathers a team of heroes to defeat him, including Captain Carter, Star-Lord T'Challa, Supreme Doctor Strange, King Killmonger, Party Thor, and a Gamora who defeated the Thanos of her universe.

At the end of the episode, Captain Carter expresses reluctance to return to her own world, but is encouraged by The Watcher, who reminds her that she is needed. In the episode's mid-credits sequence, Captain Carter, returning to the middle of a fight sequence in what seems to be a play on Captain America: The Winter Soldier's opening scene, is informed by her world's Natasha Romanoff that the Hydra Stomper, a relic of Carter's wartime efforts, has been discovered on the ship, with a passenger inside.

So, who is inside the Hydra Stomper?

Steve Rogers

By the look of joy on Peggy's face when she sees the Hydra Stomper, she is clearly hoping that Steve Rogers is inside. This would make perfect sense. Peggy identifies the Stomper with Steve, as he was the one who operated it during their time serving together in WWII. However, if it is Steve in the Hydra-Stomper, there are a few questions to be answered.

Why is he aboard Batroc's ship? Has he aged? If not, why not? Has he taken one of the revised versions of the serum? Is he even the Steve that Peggy remembers, or are the lovebirds headed for a Winter Soldier-esque amnesia plot?

Even with the possible complications, fans are already speculating that having Steve inside the Hydra Stomper may be too obvious, and too easy.

Bucky Barnes

Some believe that Bucky Barnes may be inside the Hydra-Stomper. It is worth remembering that Steve Rogers without the serum is not only skinny, but sickly as well. There are very valid reasons why he would not have been accepted into the army without Dr. Erskine's intervention. Therefore, it is quite possible that piloting the Hydra-Stomper may have eventually become too much to handle with his fragile health. In such a scenario, Steve's best friend, Bucky Barnes, may have stepped in to pilot the Stomper in his place.

It seems as though Captain Carter arrives to rescue the 107th earlier than Steve did in Captain America: The Avenger, locating them before Bucky was separated from the group for experimentation. However, this is not confirmed. Despite Bucky dodging the dangerous fall from the train that led to the loss of his arm and conversion into the Winter Soldier in the original MCU timeline, it is possible that he may have received some sort of life-extending enhancement that allows Peggy to discover him inside the Hydra-Stomper in the present day.

Howard Stark

A little less likely, but possible. Howard Stark, of course, created the Hydra-Stomper, in what was surely meant as a nod to his son Tony's eventual invention of the Iron Man suit. While Howard is established as a brilliant mind and a great pilot, he was not much of a fighter. However, neither was Tony before taking up the mantle of Iron Man. In the original universe, Howard spent a significant amount of time searching for Steve Rogers after his disappearance. It is possible that Peggy's disappearance, and Steve's retirement for health reasons, could inspire Howard to heroism, stepping in to pilot his creation himself.

If Howard has been time-displaced, this may mean a world without Tony Stark ever being born. But with a device like the Hydra-Stomper built so early, a world without Tony is not necessarily a world without Iron Man.

It has already been confirmed that Captain Carter will be revisited in What If..? season 2. We'll have to wait until then to discover the secret the Hydra-Stomper holds.