Humanoid Summons

[Rusaku]

So, it's a simple question. Is there any rule against having a summon that is humanoid? This might seem weird, but I was trying to brainstorm certain concepts to increase diversity in my characters, and a new type of summon was one that I came up with. Looking through the different beasts that were claimed, I see things like Golems, Oni, and apes. All of these can be custom made to appear human, with the qualities of their particular class. The most prevalent example would be monkeys. Enma is essentially just a regular ninja with a lot of hair and a tail.

So would anyone care if someone made - oh lets say - merfolk? I realize that there are individuals and techniques that create what may as well be merfolk already (Kisame is the prime example) but that's why I'm just using this as a rough outline. Most summons at base are sophisticated enough to have entire cultures, like the toads or whatever custom animals people have come up with. So would it be that big of a deal to create a summon that while shaped like a human, retain qualities that clearly make them different?   

[Uchiha Madara]

I don't believe having a humanoid summon would be an issue, there are both custom and canon humanoid summons already in existence. As long as its treated as a different creature (along with other reasonable expectations of a summon), you sir are golden.

[Timothy]

I personally don't have much objection myself. If say you wanted to do something like forest spirits that inhabited old trees and were humanoid, could be interesting.

[Rusaku]

I personally don't have much objection myself. If say you wanted to do something like forest spirits that inhabited old trees and were humanoid, could be interesting.

https://narutoprofile.wikia.com/wiki/Ents

Well, do I have a summon for you...