Shiloh takes her bulldog out for a walk on March 7, 2012 in New Orleans, LA. Credit: FameFlynet, Inc

Happy Birthday, Shiloh Jolie-Pitt!

On Sunday, Brad Pitt and Angelina Jolie's eldest biological daughter turns six, and Us Weekly is celebrating the tot's special day by looking back at her cutest moments to date.

In addition to wearing her older brother Maddox's hand-me-downs (she's sporting his Ramones shirt in the pic above), Shiloh is always the quickest out of the Jolie-Pitt brood to put on a funny face for the cameras.

As for her style -- boys clothing -- mom Angelina, who just got engaged to longtime partner Brad last month, says that Shiloh is definitely one of a kind.

"Shiloh, we, feel, has Montenegro style," the mom of six told Vanity Fair in 2010. "It's how people dress there. She likes tracksuits, she likes [regular] suits. She likes to dress like a boy. She wants to be a boy. So we had to cut her hair. She likes to wear boys' everything. She thinks she's one of the brothers."

Jolie also told the British magazine Stylist: "I want [Shiloh] to do what's in her heart and what's in her heart is to dress like that, I think it's beautiful."

Click here to see a gallery of how Maddox, Pax, Zahara, Vivienne and Knox's pint-sized sister always manages to stand out!