Guess Which 'Mean Girls' Stars These Cute Kids Turned Into

It's October 3rd, which can only mean one thing ... it's "Mean Girls" Day! And for today's Guess Who, you're getting a double dose of Burn Book royalty.

On the left, we have a child whose limit does not exist ... because she's been an A-list actress since she was a kid.

And on the right, we've got the tiny tot who will grow up to become the heartthrob of North Shore High.