I visited a friend, their 4 year old was watching YouTube on a tablet

At some point I sat next to him to see what he was watching, It was a cartoon where the one character looks evil and has long claws, catches another, stabs it with its long claws, cuts its head off, holds its corpse about it and drinks litres of blood gushing out. Then gains an aura, pupils dilate and sprouts wings and flies into the sky to attack more creatures.

This wasn't some Anime, it's a kids cartoon made for very young kids.

I started watching happy tree friends etc. when I was like 13, but what the fuck this is next level.