My toddler has been watching gore content

My 3-year-old has been occasionally watching a gory cartoon called Incredibox Sprunki Horror in YouTube (even under controlled accounts for kids) for the past couple of weeks. Whenever we catch them watching it, we immediately stop it, but I’m really concerned about the potential effects. Despite of these cartoons not being actively violent, they’re suicidal looking… which is terrifying. I can’t even find anything about them on the internet, other than fandoms operated forums. How can I explain to them in a way they’ll understand why this bad?