Sara is a catgirl with teal eyes, a brown cat tail, and long brown hair featuring salmon-colored ends. A beauty mark sits on her right cheek near her mouth. Her typical outfit consists of a yellow crop top and miniskirt with deep pink ruffle trim, a matching cropped jacket, green earrings, a black choker, pink boots, and red gloves with heart cut-outs. She wears a distinctive hat shaped like cat ears, adorned with a green jewel. Later, she appears in a white strapless wedding minidress with yellow-furred trim, a large bow, matching gloves and boots, and a white choker, while retaining her hat and earrings.

The daughter of the President of South Island, Sara grew up privileged, contributing to a spoiled and bratty demeanor. Material wealth fueled dramatic outbursts when denied her desires or when friends faced danger. She and her father first met Sonic during a battle against Dr. Robotnik on South Island. As a teenager, she developed a fondness for Sonic after repeated encounters, especially following multiple kidnapping attempts by Robotnik. During one significant incident, Hyper Metal Sonic nearly destroyed the island and almost killed Sonic, but Knuckles and Tails rescued Sara.

Her personality blends feistiness, bravery, and a short temper. She shows no fear toward dangerous figures like Dr. Robotnik or Hyper Metal Sonic, reacting violently to threats against those she cares about, such as physically attacking Metal Sonic to protect Sonic. Initially selfish and lacking empathy, she openly stated disinterest in her father's well-being, prioritizing only herself and Sonic. However, deeper concern for her father surfaced when he faced mortal peril, revealing a more complex emotional core. She also demonstrates intelligence and a willingness to use persuasion, like flirting with or kissing Knuckles on the cheek to motivate him into action.

Dr. Robotnik's manipulation drastically altered her path. After being taken hostage again, he brainwashed her into believing she was a villain, twisting her affection for Sonic into hatred, leading her to join his team. Robotnik explicitly aimed to force her into marriage to repopulate the world after its destruction, a prospect she found repulsive. She repeatedly rejected his advances, attacking him with a scratching technique mimicking a cat's behavior and expressing fury at becoming his bride. During this captivity, Robotnik gifted her the wedding dress, which she continued wearing afterward.

Sara possesses no supernatural abilities but exhibits enhanced physical traits. She shows notable durability, surviving a high-impact collision involving Sonic's Spin Dash inside Metal Robotnik's cockpit and remaining relatively unharmed when the mech collapsed on her. She displays surprising physical strength, overpowering Dr. Robotnik multiple times—threatening him as a hostage, knocking him unconscious with a pipe, and forcing his compliance. Her combat skills include instinctive scratching attacks and delivering forceful kicks, like repeatedly striking Metal Sonic's head after an invasion of her privacy.

Her relationship with Sonic centers on a strong, possessive crush; she frequently calls him "my Sonic" and prioritizes his safety above most else, actively intervening in battles to protect him and physically assaulting his threats. Though their past remains unspecified, their bond was close enough for her to use their connection as emotional leverage, urging Sonic to save the Land of the Sky for "the two of us." Conversely, her interactions with Knuckles involve tactical manipulation; she kisses him to persuade him into aiding her father or helping avert disasters, leveraging his visible embarrassment.