How can I disable certain content on my boys YouTube?

My son watches A LOT of YouTube and I think it's making him weird in the head. He s been watching these "undertale" and "Minecraft + five nights at Freddys". I'm aware of what these games are and i think they re amazing games, but as we all know, they have some weird communities. So here comes the question. Can I block certain content types on his phone?

Yes and no. Yes all you have to do is got youtube and if you're on a mobile phone like you have said then go to settings and choose Filter on this will block out any content that YOUTUBE has decided is not acceptable for your boy but the same time no because again you tube themselves will Filter out the not acceptable content problem is that in by doing this the minecraft and the five nights at freddy's might not be blocked ( DEPENDING) on the channel and content.