Continuity mistake: In the scene where Grug is chasing after Guy, they both wind up stuck in a tar pit. After successfully escaping they are covered in tar and Grug even gets himself stuck to Guy. In the next scene everyone is running from the exploding ground up between the mountains and both Grug and Guy are completely clean and free of tar.
Continuity mistake: During the Croods' journey to the mountain they travel through several different areas including a lake, yet in some shots the background to the mountain shows a clear, open field of nothing.
Continuity mistake: When Eep meets Guy at the fire for the first time, she throws a big rock at him. He yells in pain, and you can see his leg is pinned. But as she picks him up and sniffs at him, the rock is two or three feet away. Even if the rock rolled off his leg, it was way too heavy to lift him up with no effort at all.
Continuity mistake: At one point, Grug gets bitten in the bum. It's clear that his undergarments are made from lion skin. Yet in the next shot where he's climbing down, his undergarments are now just plain gray.
Continuity mistake: When Grug rescues Douglas, Thunk's pet, the creature is holding the blue seashell that they played fetch with. In the next scene, the family are all blowing on their shells in mourning for Grug and Thunk has the exact same seashell. It's possible he found a replica, but not likely.
Continuity mistake: When Grug throws Guy, check out the Giant Rock, in the next shot, it's vanished.
Continuity mistake: At several points in the film the mountain is further away from the Croods' position even after they are obviously closer to it then when they started.
Continuity mistake: When the family reaches the lake where they are swimming there is no visible land mass in the background even though they are supposed to be just a few miles from the mountain.
Continuity mistake: In the scene just after the popcorn falls on them, Epe picks Guy up. As Grug speaks to Epe, look at his feet, there's nothing but ground. After Epe explains what if the birds came back, and Gran enters the scene, the camara shows Grug with the log behind him, at his feet.
Continuity mistake: In the scene where Guy gives Epe her shoes, she shrieks. They are alone in that screenshot. Then as they turn away, Grug stands behind them.
Continuity mistake: When Grug runs out of the cave in the beginning, he scares the dog-like creatures away. At first there are only six creatures. In the next shot, another one is added, in which Grug scares away last. (You can tell he's new because he's a different color than the rest).
Continuity mistake: Gran's excessive body hair completely disappears after we see it the first time.
Continuity mistake: The position of Grug's family on the wall that he draws near the end of the movie changes when the camera reveals the full image. This is especially noticeable when Granny is further away from Ugga.
Answer: The family convinced Grug that Guy had skills to help them navigate the situation they are in.
MovieFan612 ★