Those are not the 'people singing the song'. They're guest stars. Hevisaurus are singing the song. Listen to other Hevisaurus tracks to hear more of what they sound like. I love the whole idea. A lot of rock and metal songs are about late nights in seedy bars doing dr*gs with mucky women. Laudable and wonderful, but not subject matter I want my 8-year-old singing along with, whether they understand the words or not. Also, the CC captions will show you that the marvellous growlcore bit is in fact the band's chef telling them what he's making for dinner. Truly beautiful.
Honestly I'm happy that I discovered it by accident and my 3yo fell in love instantly. It's great to have children's metal as an option because those normal children's songs are tireding for not normal parents. My daughter loves this music, she has learned to sing these songs (we're not Finnish, we're Estonian so languages are similar) in perfect Finnish meaning she's learning a new language. Even my 11mo starts dancing when my daughter requests her daily dose of Hevisaurus. Such an awesome project and I think by now they have translated these songs also to English, Spanish and German. At least that's what I've seen in YT watch reccomendations.
Maybe this is how we like to entertain our children and not get boored youself. Or maybe this is how we brainwash the kids to be metalheads 🤘. Bruce Dickinson once sayed that Helsinki is the heavy metal capital of the world 👌