This song is named 489 which is kinda terrifying but it recognized something from the amazing world of Gumball but fan-made and the episode is called the Joy where Gumball begin becomes evil and kills everyone except for anais and Darwin and you see that colourful liquid on them it's it's spreading everywhere on the school and on the students that have been infected thank clean Nicole and Richard Watterson came to the rescue to protect them from Gumball and they used to wear that mask to cover their mouths so they wouldn't get infected in the mouths