If you spot a black and white cat running around San Francisco International Airport, don’t be alarmed, it’s just Duke Ellington Morris, one of the airport’s newest staff members.

‘Duke’ as he’s more casually called is a 14-year-old feline and the newest member of a team named the ‘Wag Brigade’.

“Purrlease welcome our newest Wag Brigade member, Duke Ellington Morris!” the airport announced on Twitter, on June 9.

Launched in 2013, the Wag Brigade programme is designed to use specially trained animals to help calm travellers in the SFO airport terminal.

Originally, the team was ‘canines only’ but other animals have slowly joined the ranks including Alex the rabbit and LilLou the pig, who became famous as ‘the world’s first therapy pig’.

However, not just any animal off the street can don the “Pet Me” vest and roam around the terminals. All animals must be certified by San Francisco’s SPCA and complete its Animal Assisted Therapy (ATT) Program.

Animals are specially chosen based on their temperament and behaviour, the airport said. Given Duke’s CV, he was a shoo-in for the role as he has already worked as a support animal.

Life was hard in the beginning for the black and while feline, who was found starving and sick in a feral cat colony in 2010, according to the airport. After being discovered, the kitten spent a short time at SPCA, where he caught the attention of a 5-year-old girl and her mother, who were looking for a pet.

The new owners gladly took him home where they soon realised Duke was a special cat and had him certified as an animal therapist. Since then, he has helped humans deal with hardship, illness and stress. In SFO, he’ll play a similar role, and bring comfort to travellers in the airport who need it.

Duke is even marginally Instagram famous, with a profile run by his owners. After making it onto the Wag Brigade, the profile showed a post of Duke in a fake pilot uniform with the caption: “Happy is not the word…elated!”