Which Celeb Has a Serious Six-Pack?

Which mom of two still has rock-hard abs? Guess now!

This famous singer has two kids, but she's still managed to keep her abs in fighting form!

At a recent concert, the singer showed there's no doubt she's still got her rock-hard six-pack intact.

Think you know who this ripped torso belongs to? Find out after the jump...

It's Gwen Stefani, rocking out on stage with No Doubt right here in California.

Can you believe her bangin' bod?