A few months ago somebody asked me in an e-mail whether Hannibal For King is natural and my answer was: "I don't know".
Some people probably could achieve a body like Hannibal's naturally. All you need is very good genetics, diet and training. However it is absolutely possible that Hannibal himself is not clean.
In some pics he looks like he had gynecomastia removal surgery. Gynecomastia (most common side effect of steroid usage) is basically growth of breast tissue due to hormonal imbalances in favor of the female hormone estrogen. It's common after abuse of steroids because when you end a steroid cycle your natural testosterone production is really low and it needs time to get back to normal. That's why for a certain period the estrogen levels are higher and you grow "bitch tits". People usually take some sort of estrogen inhibitor in order to avoid similar problems. However, it still happens even when using steroids like anavar which are supposed to be "gynecomastia free."
In this picture Hannibal's chest looks like it has undergone gynecomastia removal surgery - once you have gynecomastia you nipples are never the same. Of course you can have gynecomastia without ever using steroids but not at that age and the chances are really slim.
With that being said without knowing more details about Hannibal I cannot tell 100% whether he is clean or not. I do believe his level of development is achievable naturally for some but I will not be surprised if he has used anabolics.
Remember - famous people want you to see what they want you to see. A lot of times the "good genetics" of Mr. Beach Body are actually not so good.