Factual error: The opening shot of the Statue of Liberty shows the statue's left arm to be raised too high. The real statue has its left arm close to its midsection, whereas the statue depicted here has its arm nearly raised to shoulder level. (00:00:01)
Continuity mistake: Ogress is depicted as having five teeth. Two on top, and three on bottom. When she is saying to the Thing "Your chivalry is wasted on me," the bottom-middle tooth disappears. (00:08:50)
Continuity mistake: When She-Hulk deflects the potted plant that Ogress throws at her, she gets dirt in her hair and on her arms and legs. When the shot changes, her hair and limbs are suddenly clean. (00:10:10 - 00:10:40)
Continuity mistake: When She-Hulk is talking to Hulk by the torch on the Statue of Liberty, she is standing directly in front of the Thing. When the shot changes, she is instantly a few feet away from the Thing. (00:19:57)
Continuity mistake: When the Thing is crumpling the flyer between his hands, the flyer alternates between being white and the same orange color as the Thing.
Continuity mistake: When the cage is dropped over the Thing, you can see it is a big solid rock slab on top of wooden bars. When the shot changes, the inside of the cage somehow fills up with bananas, even though there was nowhere for them to drop directly into the cage from.
Continuity mistake: When Hulk says "Thing? Hulk enemy," he raises his right fist while standing face-front towards She-Hulk. When the shot changes, his fist is immediately out of shot and he is now standing shoulder to shoulder with She-Hulk.
Revealing mistake: When Hulk jumps out of the river towards the New York skyline, he disappears into thin air.
Other mistake: When the forklift driver gets distracted by She-Hulk and crashes into the stack of metal vials full of flammable liquid, Bruce and She-Hulk don't hear any of the commotion until the explosion happens, even though they are only a few yards away. The crash and the falling metal vials should have been loud enough to alert them.
Other mistake: When Bruce Banner is sitting on the dock and recording his thoughts on a tape recorder, you can see that while his reflection's mouth is moving, his actual jaw is not.
Answer: The Hulk is a giant brute who smashes everything in his path when he is angry. In Ang Lee's "Hulk," General Ross, played by Sam Elliot, explains it to his daughter.