Celebrity 'Street' cred

Jonah Hill

There are certain staples of youth that we all eventually outgrow: footed pajamas, an aversion to vegetables and a fondness for all things Jonas Brothers. OK, two out of three ain't bad...

“Sesame Street,” however, is not one of them. The nearly 40-year-old show is bringing in the A-list celebrities this season to sing songs about cool shapes (hexagons!), cool numbers (the number four!) and cool-though-probably fictitious occupations (shoe fairy!).

First up: Jonah Hill may have a potty mouth, but the kids will love him. He’s just like the coolest babysitters: charming and responsible when the parents are watching—and a hilarious stoner once they’re out of the house.