The Return of the Beast: Part 2 - S1-E2
Continuity mistake: When the Leader is preparing to force Banner to transform into the Hulk, he shoots Gargoyle in the left shoulder with a blaster for being insolent, which leaves a hole in the corresponding area of his clothing. Moments later, the hole has disappeared.
The Return of the Beast: Part 2 - S1-E2
Other mistake: After the Abomination abducts Bruce Banner from the cavern, he causes a complete cave-in at the entrance. When Rick and Betty come to, they are able to see perfectly fine despite the sun being completely blocked out. Rick even states when he and Betty start to remove all the rocks that are blocking the opening that they need to find some blue sky before they can find Bruce.
The Return of the Beast: Part 2 - S1-E2
Continuity mistake: When Betty and Rick are attacked by the giant scorpion, the other mutated desert creatures appear perched on the humvee from out of nowhere.
The Return of the Beast: Part 2 - S1-E2
Factual error: When Betty's humvee breaks down in the middle of the desert, she gets out and steps over a scorpion. The scorpion is shown to have 10 legs (4 standard legs and 2 pincers). Scorpions have 8 legs.
Suggested correction: A scorpion's pedipalps (their pincers) are not legs. Scorpions and other arachnids have 8 legs and 2 pedipalps.
The Return of the Beast: Part 2 - S1-E2
Continuity mistake: When Thunderbolt Ross is talking about cutting a star out of the Hulk's hide, he is leaning against what remains of a wall after a hole was torn through it. When the shot changes to the Leader watching Ross through his insect drone, the section of the wall that was directly in front of Ross is now missing.
The Return of the Beast: Part 2 - S1-E2
Continuity mistake: When the Hulk is fighting the army helicopters in the desert, the color of the sky and the position of the sun indicate that it is twilight. When the Hulk takes cover in the canyon, the sun is setting at an unrealistically rapid pace. It transitions from twilight to nighttime faster than the helicopters can travel a quarter mile.
The Return of the Beast: Part 2 - S1-E2
Continuity mistake: When Talbot asks Betty why she is always helping the Hulk, they are standing next to a pipeline. When the shot changes, they have instantly moved several feet away from it.
