The Land Before Time VII: The Stone of Cold Fire2000

Grandpa:
It just sounds like Pterano is up to his old tricks again.

Littlefoot:
Er, what old tricks?

Grandpa:
Oh - well let's just say that if we hadn't put a stop to Pterano, we might never had made it to the Great Valley.

Littlefoot:
That's awful!

Grandpa:
Yes, it was... Someday, when you're older, I'll tell you about it.

Littlefoot:
Oh, why do I have to wait until...

Grandma:
In the meantime, remember, Pterano considers he knows everything, even when he knows nothing.

Grandpa:
So be careful, will you?

Littlefoot:
OK, I promise.