The first hunting scene with the Croods. The physical and tactical strength of each family member is displayed to glorious effect. "RELEASE...THE BABY!" indeed.
When Guy shows the Croods minus Grug the stars.
When Grug and Guy defeat Chunky and get out of the tar pit together. The indication that Grug is stepping up as a surrogate parent for Guy also makes it heartwarming.
When Grug single-handedly saves the entire family through his strength.
Every time he does this. Which is often. The guy turns into Batman when it comes to protecting his family.
When Grug realizes he needs to stop thinking "What would Guy do" and instead think "What would I do", so that he can play to his own strengths.
Said idea is sort of a Chekhov's Armory of things that Grug uses to get back to his family. And it works so well.
Not to mention that the end result involves flight, something that we in Real Life have been struggling to achieve for at least a few centuries. Yet Grug found a way to do so in what appears to be several minutes! Now that's what I call an idea!
From Eep's ending narration, "We changed the rules." Essentially giving humanity it's modus operandi for millenia to come.