A hairless chimpanzee that became an internet hit when a film of an apparent fight went viral has died suddenly.
Mongo, aged 22, had suffered alopecia and was undergoing a routine health check at Twycross Zoo, but failed to come round from the anaesthetic.
The film of the “fight” was viewed more than a million times online, fuelled in part by Mongo’s appearance.
Twycross Zoo said it was “displaying” rather than fighting and was perfectly normal behaviour for chimpanzees.
In a statement, Twycross Zoo said his death was unexpected.
“Mongo was undergoing a routine health check to investigate his enlarged air sac,” said the statement.
“Although Mongo showed no other outward signs of ill health, the health check revealed that he had an infection and regrettably, he failed to recover from the anaesthetic.”
Despite being hairless – inherited from his equally smooth father Jambo – Mongo was a hit in his group.
Early in life he had to work hard to be accepted but was recently an integral part of the strict hierarchy, headed by his father.
He was also popular with the ladies, particularly Noddy, who was usually close by.
A spokeswoman said: “A good natured and playful chimp, Mongo was often seen interacting with others – Tuli being a favourite playmate – and was just as popular with the keepers and other staff here at Twycross.”
Hundreds took to the zoo’s Facebook page to offer their condolences.
Marie Cross wrote: “Aw no so very sorry to hear this , RIP Mongo love and thoughts to his carers we will miss you lad x”
Staff at the zoo will carry out a full post-mortem examination after early checks revealed he also had some signs of heart disease.