Needs work
I am quite impressed that you managed to get such a high rating. If you are still taking requests for turning this into a series, I would prefer that you not. It is not mean or vicious, it is just an idea that is not well executed. I could not help but think that the animation was intended to be a joke because you were on drugs when making this. I just have so little clue as to what is going on here. Is that guy supposed to be a horned monster or just some really weird looking guy?
His head is actually designed fairly well, it's the rest of his body that needs improvement. It's weird how he has black blood and I could not understand the punchline if there was supposed to even be one. You should probably put in some more dialogue. While there is only one character, you can still have him say some cool stuff. Either that or have him do more so that details show rather than tell.