There is mounting concern a game which encourages users to cause themselves harm, and in some cases led to suicide, is "targeting" children.
It has led to the PSNI to put out a Northern Ireland-wide alert to warn the parents of the potentially deadly dangers their children could be exposed to.
The "Momo Challenge" has swept the online gaming world.
It first appeared last year. The menacing-looking Momo character lurks behind apparently innocent-looking games in the hope that while a parent's attention is distracted it appears and challenges or dares the gamer into "grotesque" acts of self harm.
It has also been found to appear in the middle of apparently harmless YouTube videos popular with youngsters.
The female character with distorted face, bulging eyes and a repulsive grin has also encouraged people to message it through Whatapp where again worrying instructions are made.
Momo also tells the user it's a secret and they are not to reveal anything to their parents.
Reports in Europe and around the world have linked the game to suicides of young children.
There have been numerous reports on social media of people from across Northern Ireland seeing the character pop up while their children played a game or watched a video.
One Belfast mother said she found it on her seven-year-old daughter's iPad. The woman said she was filled with dread to see the character appear despite having the proper parental controls in place.
Another said she found it on her son's PlayStation. While one woman reported seeing it suddenly appeared while her three-year-old daughter was watching a 'surprise Eggs' video.
On Sunday the PSNI issued a warning to the Northern Ireland public saying it was "targeting our kids". A spokeswoman said there had been no reports made to them, but if anyone had concerns to contact police on 101.
"Our advice as always, is to supervise the games your kids play and be extremely mindful of the videos they are watching on YouTube," said police.
"Ensure that the devices they have access to are restricted to age suitable content."
Mayor of Causeway Coast and Glens Borough Council said she had reports it had reached the north Antrim area.
"Parents and relatives of young children need to be very aware and vigilant and report to Police," said Joan Baird.
There has also been calls for social media companies to do more.
Belfast councillor Dale Pankhurst said he was aware of it circulating around the city and urged parents to make their kids aware of the dangers. He said those behind the game "deserved jail time".
The NSPCC has said that parents must make children aware of the risks online. It has published advice and guidelines for parents on its website and more help can be found at New Aware - a guide for parents on social media and gaming apps.
Parents can also contact the NSPCC Helpline on 0808 800 5000 or for children feeling worried about something they have seen can contact Childline 24 hours a day, online and over the phone, on 0800 11 11 or by visiting www.childline.org.uk.