Almost nothing is known of Harmon's past, other than that she became a zoologist and a major aide of Dr. Catherine Viciy in her research to clone a saber-tooth tiger(Smilodon fatalis), as well as other things unimportant to the plot of the film.
Kara Harmon made her debut in the film at the home of Anthony Bricklin, and was introduced by her boss, Dr. Catherine Viciy, after asking if the saber-tooth tiger they had cloned had arrived yet. Learning that it hadn't, Harmon made an imput that there could have been a problem with the driver's truck. As Bricklin and Viciy left to go check it out, the former told her to do something useful in their absence. After Viciy's ex-boyfriend, Robert Thatcher, a professional big-game hunter and tracker, is hired to help them find the saber-tooth(he was fooled into believing it was an African lion), Harmon, Bricklin, and Viciy all decided to accompany him, with them arriving a little later than planned at the rendezvous point. Once there, Harmon handed Thatcher a syringe pole and asked him if he had ever used one, to which he answered yes and asked if she had any syringes to go with it, which she produced in a black, plastic case, along with some tranquilizer. The group set out into Sierra Nevada to track the saber-tooth, Harmon studying its tracks after Thatcher found its trail. After approaching a cabin Bricklin had pointed out, which had its door smashed through and spattered with blood, Thatcher and Bricklin went in after it, with Harmon and Viciy remaining outside, her suggesting they take a look around. After Thatcher informed them of a dead man remains inside and to call the police on his satellite phone, Harmon carried her his backpack(unaware Viciy had tossed the phone away unseen), afterwards, following the deception of the saber-tooth being a lion, stated she knew then animals when Thatcher decided to abandon the hunt to get the cops, only for him to retort that he knew them as well. After Harmon stated that he should know then that they could travel 40 miles or more in day, Viciy convinced him to continue the hunt for a least the same amount of time. Later that night, after Thatcher had left to search for other campfires along the ridge, Harmon had a change of heart of their deception, and tried to leave to reveal the truth about the saber-tooth to him, despite Viciy's disapproval, and panicked about the cat capabilities and Thatcher's disadvantage, before the saber-tooth leaped on her and dragged her away, with Harmon screaming for her life. She was later killed and devoured by the beast, with Thatcher later finding her remains.
As a zoologist, Harmon was undoubtedly quite knowledgeable on animals, and seemed to have a lot of expertise on the subject of prehistoric life as well, enough for Dr. Catherine Viciy to hire her services when trying to clone a saber-tooth tiger(Smilodon fatalis), a roject they succeeded in completing. She also appeared to have some knwledge and skill in live animal capture, providing Robert Thatcher with a syringe pole and tranquilizer to aide him in their hunt for the saber-tooth when it escaped. She stated to know and understand lions and how they are.
Kara Harmon was a loyal subordinate to others, and played along with the deception of the saber-tooth being an African lion initially, but in the end, she felt guilty for lying to Thatcher about the cat and tried to defy her emplyers orders and tell him the truth, an act which led to her demise at the saber-tooth's hand. She seemed very friendly and polite to others, but when worked up had a tendency to panick and overreact to a situation.