South Lantau is today mourning the loss of Billy, the beloved cow who ran with a buffalo herd and became friendly, perhaps too friendly, with visitors.

Billy was found dead in the wetland field at Lo Uk after being missing for two days, according to Jean Leung, the friend and champion of Pui O bovines.

His cause of death is uncertain, but eight-year-old Billy had been unwell for some time, a result apparently of the consumption of plastic and other trash.

Three years ago government vets wanted to put Billy down after he became ill from eating rubbish or contaminated food.

Jean persuaded them to release him back to Lantau so he could live out his days with the buffalo.

But Billy was in fact lucky to make it to adulthood. At four months he lost his mother in a dog attack on the catchwater.

According to local vet Dr Joe Laraya, Billy suffered a giant puncture in his rump that required daily cleaning, meaning he could not be let back to the herd.

So Billy stayed at first with Joe and his partner Okka Scherer, and then in Ham Tin with Mel Potgieter, best known as the inspiration behind the Lantau Beer Dash.

As Mel explained in an interview in 2014, Billy grazed on her lawn but was keen to be a part of the family.  He would eat the dogs’ food, force his way into the house and rub himself against people’s backsides.

As he grew bigger they took him for walks, where he became friendly with the buffalo herd, to the point of challenging some of the males.

It became harder and harder to bring him home. Eventually, Mel got “fed up” and let him go.

He became a part of the Pui O buffalo herd and for years was a local landmark and talking point. Mel points out that when the herd was harassed by dogs they protected Billy equally – he was one of them.

But Billy lived a second life as an unofficial mascot of Pui O beach and a scourge of visitors to the picnic site. Most had never encountered a cow before and had no idea of how to deal with a bovine showing a healthy interest in their lunch.

It made for occasional spontaneous friendly encounters but also headaches for lifeguards and AFCD staff who had to separate Billy from the uneasy tourists shielding their lunch.

Sadly, Billy was unable to resist the trash that visitors left behind. Bins too often overflowed with too many things that found their way into his stomach.

He never fully recovered from the incident three years ago, but as Jean said, he was able to “live more than three years because he liked to stay with his family, the buffalos.”

Billy’s intelligence, friendliness and placid good nature brought pleasure to so many. He will be missed. RIP Billy.