Kelli Berglund turns 20 years old today! While you may know her best from her starring role on the Disney XD show, Lab Rats, the actress had an early role you probably didn't know about.

Way before Disney, she starred in Hip-Hop Harry back in 2006 — and she looks unrecognizable. Um, she's grown up a lot.

MORE: 14 CELEBRITIES YOU HAD NO IDEA WERE CHILD STARS

Click through the gallery to see more celebrities who starred in kids' shows before they were famous, and let us know which photo shocked you the most in the comments!