Police have warned parents that the online character 'Momo' has returned with a vengeance and is being inserted into versions of the viral 'Baby Shark' videos.
Spanish police believe sick internet users are bringing the character back to life by dropping it into 'Baby Shark' videos and other social media clips aimed at children.
The 'Momo Challenge' first made headlines last year when it saw WhatsApp users enticed to contact 'Momo' - a scary looking female figure with bulging eyes.
After contacting the character, users were said to receive graphic images along with instructions to perform dangerous tasks that even included suicide.
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It made headlines again earlier this year when it began appearing in children's YouTube videos, including Peppa Pig, and scaring children.
A police social media campaign warned parents: "No, Momo does not exist, it is an old viral character that has resurfaced with some damaging modifications.
"We have to work together to not allow it to spread."
The local authorities announced that they are investigating numerous online videos while asking parents to "supervise what videos their children watch online, especially the younger ones".
According to local media, there is one video which features the character saying: "Hi, I am Momo. I want to play with you.
"Look for a knife in your kitchen and cut your little hands. If you do not do it, Momo will come after you."
The police have asked citizens to report anything suspicious they see on social media immediately.
Momo had previously been edited into children's YouTube videos, including those of Peppa Pig .
Using a computerised voice, the ghoulish character issues horrific threats to whoever has clicked on the video.
Keisuke Aiso, the guilt-stricken artist who created Momo , says he feels "responsible" for the widespread panic and fear caused over the last few weeks .
His work was hijacked by warped sickos who used it in the so-called Momo-challenge.
But the Japenese artist, 43, said Momo is now dead.
Speaking from his studio near Tokyo, Japan, he said: “It doesn’t exist anymore, it was never meant to last.
“It was rotten and I threw it away. The children can be reassured Momo is dead - she doesn’t exist and the curse is gone."
