Bree Blackburn (voice: Marisa Tomei) is Sloan's wife and the hidden secondary antagonist of The Wild Thornberrys Movie, where she acts as one of Sloan's co-poachers along with another group of poachers.
Bree first appeared as a veterinarian aiding a wounded rhinoceros whom Eliza Thorberry consulted. The park rangers took over from that point. The couple offered Eliza a ride back to her parent's camp but she declined.
Eliza, Darwin, and Donnie would later encounter the two in their campsite where they attempted to contact the park rangers over a plot by poachers to murder a herd of elephants in Timbo Valley. The following day, Eliza discovered in the pair's RV the cheetah cub Tally, who was previously caught by poachers in a previous encounter. It was here that the Blackburns true color's were shown: they were the poachers plotting to kill all the elephants in Timbo Valley. Sloan and Bree captured Eliza, Darwin, and Donnie, restraining them with zipties.
Sloan demanded to know where Eliza got the information from, fearful of her knowledge that it might cause the authorities to intercept their plan. Before Sloan could interrogate Eliza on what else she knew, Debbie arrived looking for Eliza. Sloan threatened to kill Debbie if Eliza didn't reveal how she knew this (while Bree just tells Sloan to kill Debbie anyway) forcing Eliza to reveal the truth about her power and lose it as a consequence. The resulting supernatural storm that started up as Eliza's power was taken back prompted Sloan and Bree to leave the Thornberrys behind and flee by chopper.
In Timbo Valley, Bree was seen piloting the helicopter while Sloan remained in contact with fellow poachers stationed on the cliffs. The other Thornberries sabotaged the charges that would have sent the elephants panicking into the electric fence they set up. The poachers almost succeeded in murdering all the elephants, but their plot was foiled when Eliza managed to stop the elephants and turn them around just before they reached the fence. Enraged at Eliza's heroic interference, Sloan forcefully picked her up on the chopper's ladder and hurled her into a waterfall where she is later rescued by the Shaman.
Sloan attempts to shoot the elephants down with a shotgun, but the angry elephants begin pulling down their chopper using their trunks on the ladder hanging below. With the Bree losing control of the chopper, the two bailed out and hit the floor. Upon the end of the eclipse, Sloan and Bree were cornered by the angry elephant heard. Thankfully, the Park Rangers and the Thornberry's arrived on time to spare them from a much worse fate. The pair were then arrested on charges of illegal poaching. Bree tried to reason out that they were "trying to help the elephants" an obvious blatant lie. The other poachers of the group were presumed to be arrested as well.
Bree and Sloan initially appeared as a friendly, warm, charming, and kindhearted couple of animal-loving zoologists. They appeared to be friends of Eliza. This was a cover as they were revealed to (in fact) be cruel, greedy, threatening, destructive, murderous, sneaky, evil, and ruthless poachers and the ones responsible for kidnapping Tally. Bree and Sloan were also prominently behind a poacher plot to take advantage of the migration of a thousand elephants to Timbo Valley during a solar eclipse to massacre the elephants by driving them into an electric fence for their ivory.
She is a skilled helicopter pilot.