Everyone knows the Hulk - he's big, green and definitely one of the best superheroes. He's the exact opposite of the quiet scientist Bruce Banner, and the two aren't always happy to share the same body! But how well do you really know the Hulk? Check out these epic Marvel facts to find out!

1. He has super-stretchy pants!

How else would his pants stay on after all his other clothes have ripped off? But the Hulk's underwear aren't just made of any old stretchy material, they're made specially by one of the Fantastic Four.

2. Gamma radiation is real

Unlike vibranium, adamantium and other bits of superhero science, gamma radiation is a very real thing. It can come from space and even mutate and change DNA, but in the real world this usually leads to horrible injury, not superhuman strength. So don't try it at home!

3. The Hulk wasn't really that popular

Despite being definitely one of the best Marvel characters ever, the original Hulk comics didn't sell very well. In fact, he was almost cancelled a few times!

4. The green eyed monster!

As well as getting angry, the Hulk also gets jealous really easily. In one storyline, he gets so upset at the idea of his ex-girlfriend going on a date with someone, that he tries to eat the new man. Urgh. Get a grip, Hulk!

5. The Hulk was almost grey!

When Stan Lee (the big cheese at Marvel) wrote Hulk, he originally wanted him to be grey. But back then it was quite difficult to make grey look good in comics, so they settled on green instead.

6. The Hulk can see ghosts!

The Hulk has lots of long-forgotten superpowers (more on those later)... one of which is being able to see ghosts! In fact, he's one of the few Marvel characters who can see Doctor Strange when he's in his astral form. So there you go.

7. Hulkenstein's Monster

Stan Lee came up with the idea for Hulk by mixing the classic stories of Frankenstein's Monster with Jekyll and Hyde. He was clearly a big fan of spooky stories!

8. Thanks, Bruce!

Like Jekyll and Hyde, the Hulk is basically two people at the same time. And the quiet scientist Bruce Banner is always stuck inside, constantly trying to calm the Hulk down. In fact, the reason the Hulk doesn't hurt MORE people, is because Bruce helps him work out how to flip tanks and cars over without actually crushing anyone. Safety first!

9. Rainbow Hulk!

The Hulk has been lots of different colours of the years. There was the original grey Hulk, green Hulk, dark green Hulk, red Hulk, even pink unicorn Hulk! Sorry, not really.

10. The Hulk can breathe underwater

That's right! This secret superpower allows the Hulk to go on adventures at the bottom of the sea too. There's no stopping this guy!

11. He has an amazing immune system

There are no diseases that make the Hulk sick. That's because the antibodies in his blood are so powerful he instantly gets over any cough, cold or fever he might catch. Shame it doesn't help his anger issues!

12. His blood is pretty handy

Because of the antibodies, injections of Hulk blood can be used as medicine - and have saved the lives of several Marvel characters who have been injured. Thanks again, Hulky!

13. His stretchy pants have an Emergency pocket

...Not for anything rude! No - because Bruce often wakes up from his transformations in lots of different places, he has an emergency kit sewn into his pants that has matches, a credit card and a needle and thread inside. So he can get help, and then sew the kit back into his pants for next time! Clever, eh!

14. Hulk in a Hulk mask?

In one issue of the original comics, Bruce Banner invented a machine that only turned his body into the Hulk, and left his head alone. So to keep his identity, he had to wear a Hulk mask! What??

15. Hulk has saved Bruce Banner's life

Hawkeye once shot Bruce Banner with an adamantium arrow, and whilst Bruce should have died - the Hulk didn't let him, and quickly transformed into the giant green monster. When the Hulk was done hulking, he turned back into a perfectly healthy Bruce again. That's one nifty superpower!

16. Bob Banner!

Stan Lee was famously bad at remembering names, and would sometimes call Bruce Banner Bob instead. Doesn't quite have the same ring to it!

17. Arnie Smash!

Arnold Schwarzenegger was almost chosen to play the Hulk in the movies - but he was too short. What a shame!

18. It's always Hulk time

For a while, the Hulk could only transform at night, like a werewolf. Other times, he had to have a direct shot of radiation. Nowadays, it just kind of happens randomly!

19. The Hulk gave us Wolverine!

If it wasn't for the Hulk, there would be no Wolverine in the Marvel Universe. That's because Wolverine was orginally sent to kill the Hulk - by the Canadian Government, would you believe it! They've since made up and are good friends. Kind of.

20. But not just Wolverine...

Both Thor and Daredevil first appeared as characters in old Hulk movies. So we really have a lot to thank the big green lump for!