Is The Hulk Immortal?

Well, many of the potential seeds have already been sown. We known that this version of the Hulk is practically invulnerable, that he can revive Banner if the man dies, and that the pair have some kind of ability to "handover" to one another, so to speak.

Currently, the only thing that provides an obstacle for this theory is that we haven't seen any of the other "versions" of Hulk that reside within him in Immortal Hulk - as, in the comics the less verbal, violence-prone Hulk we see in the films is merely one of many alternate versions. But then, we do see a sort of Doc Hulk in Endgame, when Banner and the Hulk end up in a weird conjoined form.

We've actually also seen signs that suggest that our "regular Hulk" is becoming the one we know from Immortal Hulk. In the scene from Thor: Ragnarok where the green bad boy becomes sad after fighting with Thor, he tells the Asguardian "I know, I'm sorry - I just get so angry all the time. Hulk always angry." This line is both in first person, and fairly long for our usual monosyllabic hero.

Based on all this the MCU could easily reveal that their Hulk has been the "Immortal Hulk" the whole time. In fact, it'd be a really interesting way for his character to progress over the next few phases - as realising you are immortal would likely throw anyone into a bit of emotional turmoil.

It also raises the badass potential of the MCU featuring any of the Hulk's evil forms as a big baddie in a future film. It might be low-hanging fruit to have one of his alter-egos go rogue, but the idea of a crazy immortal murder-machine facing against his reluctant friends is too good to not have happen.

The future of the Hulk is uncertain, but regardless of what happens, it's sure to be exciting - just especially so if it's a future that may last forever.