The 28-year-old actress refers to herself as "The Native Tiger" on the photo sharing site, and describes herself as a "child of the Cherokee tribe," "forest nymph," "Lunar Leo" and "mother goddess to 2 bohemian revolutionaries - my kamikaze free spirit & my peaceful warrior" in her bio. Her first posts have included a makeup-free selfie and inspirational quotes.
"First IG selfie," she writes. "Early morning, no makeup, filter."
Fox posted a picture of the quote "Mercy triumphs over judgement" on Saturday, and captioned the photo, "Instead of being critical & judgmental choose to live in an attitude of kindness & mercy. When you give positive you receive positive #InstantKarma." The actress had previously shared a photo of a bonfire on the beach, and included the quote, "Some women are lost in the fire. Some women are built from it."
Fox gave birth to her second son with husband Brian Austin Green in February; the couple have been married since June 2010. She will next appear as reporter April O'Neil in Teenage Mutant Ninja Turtles on August 8.
2014: The Year in Music [PHOTOS]