The Hulk is one of the most powerful and indestructible heroes in the entire Marvel Universe, and some versions of the character outliving the entire rest of the Marvel Universe. This has even happened as recently in The Immortal Hulk when a terrifying portent of the future suggested the Hulk will not only outlive everyone else readers are familiar with but will become an entirely new kind of monster along the way.
However, some aspects of that series can also be found in another Hulk story about the Jade Giant outlasting everything else he's ever known or loved before. Long before The Immortal Hulk began, Marvel took showed what a Hulk at the end of the world might look like in Peter David and Dale Keown's Incredible Hulk: The End.
WHAT HAPPENED IN HULK: THE END?
Incredible Hulk: The End opens on an old and decrepit Bruce Banner, roughly almost 200 years after the modern events of the Marvel Universe. Many of his fellow superheroes died in the "Hell on Earth" and "Outer World" wars, with only a handful making it long enough to die of old age. The final war ended with a nuclear holocaust wiping out the rest of humanity -- everyone except the Hulk. Bruce has spent years wandering the radioactive remains of the Earth during the day as the last human on the planet. Banner has long wanted to die, but the Hulk inside him refuses to go gently. At night, the Hulk breaks out of Banner and roams the world. He lashes out at the massive insects that have grown in the radioactive landscape and constantly thinks back about how much he hates Banner.
A robotic probe is the only apparent remaining technology left by an alien known as the Recorder, as it observes both Banner and Hulk during their travels. Every time Banner comes close to death or attempt suicide, Hulk breaks loose and saves the pair of them, and both constantly think about how much they hate their other half. During a rainstorm one fateful night however, Bruce has a heart attack and sees visions of all the people he cared about who are now long gone. While Bruce accepts his death, Hulk fights back, desperate to survive. By morning, Hulk remains, but the Bruce Banner persona is gone. Hulk is now fully alone in the world, and the story ends with Hulk sitting in darkness, watched by the recorder, feeling nothing but the cold in the night.
THE ORIGINAL IMMORTAL HULK
Many elements that would eventually become major aspects of Immortal Hulk pop up in Hulk: The End. Since both stories are concerned somewhat with the terrifying and tragic connection between Bruce Banner and the Hulk, they both show Banner dying -- or at least attempting to die -- and Hulk refusing to allow that end. Hulk and Banner are also separated by the time of day, as they are in Immortal Hulk. This harkens back to the original Incredible Hulk stories, where the time of day played a role in Banner's transformations.
Both comics also feature the Hulk being horrifically maimed in some way. While Immortal Hulk has featured more upsetting imagery, there's still horrifying sequences in Hulk: The End, such as Hulk's body having to heal itself after it's reduced to piles of organs and gore by a swarm of mutated cockroaches. Another notable similarity between the two teases the idea that the Hulk will outlive the entire Marvel Universe. In Hulk: The End, it's through no fault of the Hulk, who eventually just turns his back on humanity after their atomic war and waits in a cave until the rest of the species is long dead.
Meanwhile, Immortal Hulk has the reveal that in at least one possible future, the One-Below-All has been able to consume the Hulk and become one with it, wiping out major Celestial figures like Franklin Richards so that he can survive into the next universe and lay waste to all the living beings who exist within it. Perhaps the greatest connection between the pair is the idea that Bruce Banner and the Hulk ultimately need each other.
By The End's end, the Hulk is finally given his dream of being left alone by the entire world in the end, with even Banner fading away. However, this leaves Hulk alone, with nothing to rage against or fight for. This is similar to how Banner has been desperate to find some cause to ground Hulk's fury, otherwise risking something like the Devil Hulk instead lashing out. Both stories underscore the importance of having Banner's humanity around to somewhat ground Hulk, even if they take different routes in characterizing that separation as purely tragic or genuinely frightening.