Soul Suicide Challenge Momo is being deployed in children's YouTube shows like Peppa Pig, a school has warned.
Parents believe their child is sure to see a normal episode of their favorite program – but a "Momo" clip has been split into the YouTube clip.
The Momo character – a scary doll face – interrupts the show and threatens the viewer to contact a WhatsApp number.
Some parents say their children have been told that they will be "killed in their sleep" if they do not contact Momo & # 39;.
When the child has joined & # 39; Momo & # 39 ;, the person behind the account can send what they like to the child on WhatsApp.
Users are told to harm themselves and kill themselves and are threatened if they refuse to follow & # 39; orders & # 39 ;.
- Has your child been affected by the Momo challenge? Email email@example.com
"The challenge" has recently made its way to the United Kingdom that has already been linked to the suicide of a 12-year-old girl in Argentina.
A French father filed a complaint with the state department in November after his son had taken his own life.
And in November 2018, the Belgian Prosecutor reported that a 13-year-old boy had been the victim of "Momo Challenge" and hanged.
Northcott Community Special School in Bransholme, Hull, told the parents about the "disruptive" phenomenon disguised as "avoiding adult detection", reports Hull Live.
In a tweet, the school said: "We are aware that some unpleasant challenges (Momo challenge) are hacking into children's programs.
" Challenges appear midway through Kids YouTube, Fortnite, Peppa Pig to avoid adult detection .  "Be aware that your child is using it, the pictures are very disturbing."
Momo & # 39; character is symbolized by a joking woman with grotesque traits and bulging eyes.
The avatar was taken from the work of Japanese artist Midori Hayashi, who is not associated with the game.
The doll lures the kids to contact her via social media before sending them graphic images and & # 39; orders & # 39 ;.
In a letter to parents, also St Bedes RC Primary School in Carlisle, Cumbria, also warns of the "disturbing" game.
The school said, "Fancy and fun from the start, this gaming experience quickly darkens and absorbs players who are encouraged to perform acts of violence and self-harm through a series of progressively risky challenges."
It added: "The challenges of this game are one serious risk to safety, well-being and good – showing children and young people in our schools here in England, as well as the disturbing content when a player refuses to continue.
"With Worrying Similarities to" Blue Whale- The challenge "has also been associated with at least five cases of suicide in childhood. "
NSPCC says children should not feel pressured into doing something that makes them insecure.
A spokesman said: Children may find the difficul to stand up to peer press, but they need to know that it is quite okay to refuse to participate in crazes that make them feel insecure or afraid.
"Parents must talk to their children and emphasize that they can make their own choices and discuss ways to say no to .
"Soothing a child that they can still be accepted, even if they do not go along with the crowd, will help them do something that can hurt them or make them unpleasant."
In Russia, the "challenge" has been linked to at least 130 teens.
But the British police believe it is actually being used by hackers to get social media users' personal information.