How would you create distinction between Troll, Ogre, and Oni?

[Deleted member 68927]

I know that writers are free to draw up whatever they want, that is not the point of this topic, however.

Also, I am not talking about Internet Troll, so please cut me some slack and let this discussion move on the way it supposes to be.

I would love nothing else but seeing how you attempt. You can let me know what inspired your creative decision. That would be more materials to enrich myself.

Trolls: Black Desert Online big bearded old men, who smile a lot.
Ogres: Green, and LOTR style
Oni: Red skinned, and Japanese looking.