- ""If I see that animal near my house or my kids again...""
- ―Douglas Hunsiker
He worked as a pilot and despised the Rodmans for no apparent reason, clashing with them when an all too curious three-year-old Caesar (who was at the age of a human toddler) escaped and frightened his children when the curious chimpanzee wanted to ride a bicycle found in Hunsiker's garage, propelling Hunsiker to run at Caesar with a baseball bat. Hunsiker chased Caesar around, causing the frightened chimp to fall off the fence and slash his thigh on gardening tools, and almost struck him before Will and Charles arrived to save him. Even though Charles insisted that Caesar was simply being playful, Hunsiker warned the Rodmans to not let Caesar near his house or his children again.
Five years later, Hunsiker accosted Charles, whose Alzheimer's returned after eight years of his ALZ-112 treatment, over damage to his car. He refused to listen to Charles, who tried to prevent him from calling the police, and started threatening and poking Charles, which provoked an angry Caesar, who was watching from his window, to retaliate and bite off Hunsiker's right index finger. Witnesses called the police, and Animal Control deported Caesar to the San Bruno Primate Shelter.
Weeks after the incident, Hunsiker, still recuperating from his finger reattachment surgery, confronted a man who was at the Rodmans' home, and was accidentally sneezed on by the man. Shocked and enraged, Hunsiker demanded the man to leave, unaware that he had been infected with a virus. Days later, Hunsiker continued with his job and headed to the airport, listening to news reports about apes from a laboratory and the zoos escaping and traveling across the Golden Gate Bridge. Arriving at the airport, Hunsiker noticed his nose was bleeding, but paid no attention to it before heading to the terminal.
In his cockpit, he flew his plane to Paris while infecting passengers on the plane with his sneezing, which triggered the spread of the ALZ-113 across the planet, leading to a worldwide pandemic that would later be called the Simian Flu. However, Hunsiker died before the pandemic began.
Douglas Hunsiker was a crass and bad tempered man who seemed to be almost paranoid concerning the well-being and security of his property and his children, which manifested itself in acting in a hostile fashion towards the Rodmans, including their associates such as Caesar and Robert Franklin.
However, this behavior backfired on him as his unjustified attempt on the harmless Caesar's life resulted in the ape gaining a grudge, and Hunsiker's injuries resulted from this when he abused Charles. Hunsiker's tendency to meddle in neighborly affairs also exposed him to the ALZ-113 virus carried by Franklin, which Hunsiker then spread through air travel and caused a worldwide pandemic that destroyed human civilization and nearly wiped out humanity.
- An earlier version of the script gave Hunsiker's first name as Douglas. In the same script, Steven Jacobs was infected with the virus at the Gen-Sys Laboratories before taking a taxi home. Hunsiker then used the same taxi to take him to the airport, thereby infecting him also.
- In the scene where Hunsiker shows up at the airport while infected with the virus, he has a bandage and metal splint around the finger that Caesar had injured. This is also visible when Hunsiker confronts Franklin.
- He is the only ape-hating character who didn't die on-screen, unlike Steven Jacobs and Dodge Landon.
- Hunsiker must have left his keys in his car, the doors unlocked and the engine of the car turned on for Charles to have been able to try to drive it.
- Hunsiker was played by British-born Canadian actor David Hewlett who is best known to fans for his role as Dr. Meredith Rodney McKay in the Canadian-American sci-fi show Stargate Atlantis and its parent series, Stargate SG-1.
- Madison Bell, who plays his daughter Alice, was also in Stargate Atlantis with actor David Hewlett, portraying the role of his character's niece Madison Miller.