Leave it to Serena Williams to make even the sweetest baby bump look fierce.

On Tuesday the expectant tennis star and her fiancé, Reddit co-founder Alexis Ohanian, were granted a special sneak peek at Pandora ­– World of Avatar at Disney's Animal Kingdom in Lake Buena Vista, Florida. While touring the "world" inspired by James Cameron's fictional planet, Williams, dressed in cute denim overalls, couldn't resist the opportunity to unleash her inner Na'vi warrior.

"Had the best time at Disney, Pandora was unreal!! #visitpandora," Williams, 35, wrote alongside a photo of herself posing beneath Pandora's floating mountains—fake Na'vi ears and all. We have no doubt her future child is destined to be a warrior.

Williams, who accidentally announced her pregnancy via Snapchat last month, is reportedly due this fall.

According to People, the 12-acre World of Avatar opens May 27 and features two new rides: Avatar Flight of Passage, a thrilling trip through Pandora's jungles and floating mountains, and the family-friendly Na'vi River Journey, which takes guests sailing through a glowing rainforest.