In 2001, Sandy Herold adopted a chimp named Travis from a home in Missouri. He was just 3 days old. He became a local sensation, accompanying Herold and her husband to work, playing with neighbor children and posing for pictures with passersby.
Travis learned to water houseplants, dress himself in clothes, open locked doors using keys and watch TV using the remote control. He also drank wine from a stemmed glass. But it wasn't long before his behavior deteriorated [source: Associated Press].
One day, when Travis was 14, he became agitated, so Herold allegedly offered him tea infused with Xanax to calm him. That's when a neighbor named Charla Nash arrived on the scene to help contain the primate.
But Travis, in an abrupt display of violence, attacked Nash and literally tore off parts of her face, permanently blinding her and resulting in years' worth of reconstructive surgery. Nash eventually received a face transplant [source: Brown].
Herold stabbed Travis with a butcher knife, but the rampage continued. Finally, a police officer arrived on the scene and shot the animal to death [source: Newman and O'Connor].
The chimp was infected with Lyme disease (which is often carried by ticks), which can cause mental problems in the afflicted, a factor that may have contributed to the violence. Or, perhaps the Xanax triggered an emotional meltdown. No matter the cause, Travis' story resulted in worldwide outrage and sympathy for both the animal and his unfortunate victim [source: Miller].