After their cave is destroyed, a caveman family must trek through an unfamiliar fantastical world with the help of an inventive boy.

Guy: Once upon a time, there was a beautiful tiger. She lived in a cave with the rest of her family. Her father and mother told her: "You may go anywhere you want, but never go near the cliff, for you could fall."
Grug: And fall. Good story.
Guy: But when no one was looking, she go near the cliff, for the closer she came to the edge, the more could she hear, the more could she see, the more she could feel. Finally, she stood at the very edge. She saw a light. She leaned out to touch it... and she slipped.
Grug: And she fell.
Guy: And she flew.
Thunk: Where did she fly?
Guy: Tomorrow.
Eep: Tomorrow?
Guy: A place with more suns in the sky than you can count.
Thunk: It would be so bright!
Guy: A place not like today, or yesterday. A place where things are better.
Grug: Tomorrow isn't a place. It's-it's-it... Ugh! You can't see it!
Guy: Oh, yes, yes it is. I've seen it. That's where I'm going.
Grug: What is this stuff that saves you from my punches?
Guy: Tar.
Grug: No!
Guy: Please...
Grug: I have to get back to them.
Guy: Stop struggling!
Grug: No!
Guy: Grug, STOP! No one gets out of this. Believe me... I know.
Grug: Your...
Guy: Family. Yeah.
Grug: Sorry.
Guy: I was little when it happened. Last thing my parents told me was: "Don't hide. Live. Follow the sun. You'll make it to Tomorrow."
Grug: You followed the light. My daughter is a lot like you.
Guy: No. She's like you. She loves you, but always forgets to say it. Just like you forget to tell her.
Eep: [Grug hugs Eep] This is good... what do you call this?
Grug: I call it... a hug. Because it rhymes with Grug; but you can always change it if you don't like it.
Eep: No,
[Hugs Grug]
Eep: I like it.
Eep: Dad, I'm afraid.
Grug: Never be afraid.
Eep: Hey, do you have a minute? How did the tiger fly?
Guy: I only share when I'm outside the log. I'm funny that way.
Guy: You're really heavy.
Eep: [flattered] Really? Thank you!
Ugga: Mom, we're ready to leave. Mom?
[Silence, Grug Looks Hopefully]
Gran: Still alive!
Grug: It's still early.
Gran: And You're still fat!
Guy: Okay, open them. I call them shoes.
Eep: [Opens her eyes and screams in panic and excitement] I *LOVE* them! Where are my feet!
Guy: Don't worry! They're still there.
Eep: I never got to tell him.
Ugga: Eep, if your dad were here, he would tell you to...
Grug: [from afar] Get out of the way!
Thunk: Wow. You sound just like him.
[first lines]
Eep: With every sun comes a new day. A new beginning. A hope that things will be better today than they were yesterday. But not for me. My name is Eep. And this is my family, the Croods. If you weren't clued in already by the animal skins and sloping foreheads, we're cavemen. Most days we spend in our cave, in the dark. Night after night, day after day. Yep, home sweet home. When we did go out, we struggled to find food in a harsh and hostile world. And I struggled to survive my family. We were the last ones around. There used to be neighbors. Uh, the Gorts, smashed by a mammoth. The Horks, swallowed by a sand snake. The Erfs, mosquito bite. Throgs, common cold. And the Croods, that's us. The Croods made it, because of my dad. He was strong, and he followed the rules. The ones painted on the cave walls. Anything new is bad. Curiosity is bad. Going out at night is bad. Basically, anything fun is bad. Welcome to my world! But this is a story about how all that changed in an instant. Because what we didn't know was that our world was about to come to an end. And there were no rules on our cave walls to prepare us for that.
[repeated line]
Grug: Release the baby!
Grug: No more dark. No more hiding. No more caves. What's the point of all this? To follow the light. I can't change. I don't have ideas. But I have my strength. And right now, that's all you need.
Ugga: No, we don't know what's over there. Maybe nothing! It's too risky!
Grug: It's a chance.
Guy: I'll take that chance.
Grug: You know, I've wanted to throw you away ever since I met you.
Guy: Heh. That's a joke, right?
Grug: [jokingly] What's a "joke"?
[throws him over to the other cliff]
Gran: I was in love once. He was a hunter, I was a gatherer. It was quite the scandal. We fed each other berries, we danced. Then father bashed him on the head and traded me to your grandfather.
Guy: I can't believe your family has never seen rain!
Eep: We don't get out much.
Grug: [Smears mud on Thunk's face] Paintings are so passe. I call this a snapshot.
[Hits Thunk on the face with a flat rock, leaving an impression of his face]
Thunk: Can we do that again? I think I blinked.
Guy: [Referring to Belt] Don't eat him! He will cut you! He's a pet! My pet!
Gran: What's a "pet"?
Guy: It's an animal you don't eat.
Gran: Ha! We call those "children".
Grug: I guess I was just busy keeping them all alive.
Guy: It's okay. That's what dads do.
Grug: That's right! But we can't do that from here. We need one of your ideas. Come on, you can do it.
Guy: Belt! Emergency Idea Generator, activate!
[Belt hits him in the head with a rock]
Guy: OW! Ooh! I've got it!
Eep: So how did the tiger fly?
Guy: She jumped on the sun. Rode it to tomorrow.
Grug: Don't. It could be dangerous.
Eep: Dad, you always say that.
Guy: Careful.
Eep: Oh, okay.
[Grug sighs in exasperation]
Grug: Splitting up is a bad idea, it is much safer if we stay together
[Notices Guy and Eep very close and separates them]
Grug: Except for you two. You need to be separate.
Grug: Three days is not forever!
Eep: It is with this family.
Ugga: [Wearing a wig] Honey, what's that on your head?
Gran: It's called desperation.
Grug: I call it a rug. Rhymes with Grug.
[points to boulder]
Grug: And this is a ride. Also rhymes with Grug.
Guy: That doesn't rhyme.
Grug: I... have... an... IDEA!
Grug: [On a giant stone lever] I call this a "Lifterator"
Gran: I almost feel sorry for him.
[Grug's invention fails and he is flung into the sky, struck by lightning, then the boulder rolls over him]
Gran: Hahaha! No I don't!
[repeated line]
Grug: Never *not* be afraid!
Grug: [after Guy hands out shells so they can "call" each other] I don't see why the kids need their own shells.
Guy: I can help you, but we're gonna have to make a few changes around here. The log ride is over. Drop the log.
[Grug drops the log]
Guy: Now, kick it away.
[Grug kicks it one feet away]
Guy: Farther.
[Grug roars out of frustration and kicks the log so far it goes into the horizon, fading out of sight]
Guy: Really?
Grug: We're going tooooo... That mountain. Don't ask me why, just a hunch, just feels right.
Ugga: Grug, we've never walked that far!
Thunk: I don't think my feet can go that far.
Gran: I'll never live long enough to get there.
Grug: [grinning at Gran's declare] Lets do it!
Gran: What's a *pet*?
Guy: It's an animal you don't eat.
Gran: We call those *children*.
Guy: You're being irrational and counter-productive!
Grug: Big words make me angry, c'mon, keep talking.
Guy: Stay here if you want, but let me go! I've got a dream! A mission! A reason to live!
Eep: Not anymore!
Eep: [talking about Guy] I thought he was a warthog, but then he turned into a boy.
Gran: Strange, it's usually the reverse.
Eep: Hi fire.
Guy: [laughing] It's not actually alive.
Eep: But you said it was dying.
Guy: [pause] Sorry.
Grug: [when thunk attempts to eat a large piece of popcorn] N-no, don't eat it, it's new!
Guy: [watching Grug and Thunk "hunting"] What're they doing?
Eep: Hunting
Guy: No seriously, what're they doing?
Thunk: [seeing a large stalk of corn explode into fireworks] It looks like magic.
[sniffs]
Thunk: AND SMELLS LIKE FOOD!
Grug: What were you doing up there?
Eep: I don't know.
Grug: What were you looking for?
Eep: Nothing.
Grug: Why did you go there?
Eep: I don't know!
Grug: Why don't you know?
Grug: I, AM, A, CAVE-MAN!
Guy: [sees Eep watching Grug and Thunk hunt] You look tense.
Eep: [in denial] I'm not tense
Ugga: Grug, what's that on you're head?
Gran: [muttering] It's called desperation.