Continuity mistake: When She-Hulk is telling her parents that Bruce will help her, we see the Hulk sitting in the treehouse with his left leg sticking through the floor, and his left arm near the doorway. When the shot changes to inside the treehouse, his left leg is perched on the floor, and he is several feet away from the doorway. (00:08:49)
Continuity mistake: When She-Hulk is calling Gargoyle a vertically-challenged tree stump, her dress is colored pink, when it should be black. (00:11:15 - 00:14:45)
Continuity mistake: When Ogress is attacking Jennifer inside the dance club, the hair on her head and arms is black when it should be dark brown. (00:18:40)
Continuity mistake: When She-Hulk's high school classmates are shown in the car, the woman in the back waving the pom-poms is wearing a blue outfit. When the shot changes, her outfit is now purple.
Continuity mistake: When She-Hulk's high school classmates are waving goodbye to her, you can see the woman in the front passenger seat is sitting down. When the shot changes, she is suddenly slightly standing up.
Audio problem: When She-Hulk says "Hey, Hulkster, having any fun?" and Hulk responds with "A blast, yeah," he is speaking in Abomination's voice.
Continuity mistake: When Ogress has She-Hulk in a bear hug while Gargoyle is saying he can restore her to her luster, the hair on Ogress' arms is the same color as her skin, when it should be a dark brown.
Deliberate mistake: When She-Hulk walks up to the bar, she asks the bartender for a cream soda with a mint twist, which the bartender gives her immediately, with no time to pour the drink.
Character mistake: When the woman is looking at the high school photo of She-Hulk at the high school reunion, she says "Oh, look. Remember her? Jennifer something or other." You can see that her full name is written directly underneath the photo, so there's no reason why the woman would look at the photo and not know what Jennifer's last name is.
Factual error: She-Hulk's license plate reads "GAMMA-GRL." She's from Washington DC and now resides in New Mexico. Both places have a limit of seven characters on a license plate. It can't be a vanity plate either, because both places also require front and rear plates.
Other mistake: When She-Hulk is looking at her eyes in the mirror and raises her left hand to her face, only the hand in the reflection is raised. Her actual left hand doesn't raise.
Other mistake: When She-Hulk walks into her parents' house, they are shocked to discover her appearance. She-Hulk's identity as Jennifer Walters is public, as she is still a trial lawyer, and the previous episode showed that she has celebrity status. We know she and her parents aren't estranged, because moments before she tells the Hulk that they know about him, which she could only know if she kept in contact with them, so there's no conceivable way they could have been unaware of her transformation as well.
Audio problem: When Abomination is saying "I can still take him," his mouth is not moving.
Audio problem: When Bruce Banner is saying "Why, did you have another weak spell?" his mouth movement is slightly out of sync with the dialogue.
Continuity mistake: When Dark Hulk arms the nuclear warhead, the orientation of the timer is the same as the control buttons. When Banner disarms the warhead, the orientation of the timer is now upside down respective to the control buttons. (00:18:00 - 00:20:26)
Continuity mistake: After the alien entity has been purged from Bruce Banner's body, he is on all fours and tilts his head back, with the warhead behind him. When the shot changes, his head is pointing forward again and the warhead is now directly in front of him. (00:20:15)
Other mistake: When Dark Hulk lifts up the middle army tank, he rotates the tank towards the two tanks on either side of it and fires the tank gun at both of them. Since he's holding the tank from the bottom, he has no way of controlling the tank gun, and there's no reason the tank's gunner would fire on his own men.
Factual error: When the Dark Hulk is attacking the city and destroys a helicopter, the occupants can be seen with their parachutes already deployed immediately after the helicopter has exploded. Not only would they not have had enough time to already be parachuting to safety, but given that the helicopter was only a few stories high in the air, they wouldn't have had time to safely deploy their parachutes in the first place.
Continuity mistake: When the alien entity transforms Bruce Banner's body into a purple-skinned Hulk, his hair also turns black. When the shot changes, his hair is back to being brown.
Other mistake: Throughout the episode, you can see that the animators drew Doctor Strange's fingernails, even though he is wearing gloves.
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.