Advice for book writing.

[DragonDePlatino]

If you need to make your protagonist nonhuman to reinforce their character, that should be setting off some alarms. Its a common mistake for writers to change a character's appearance or species to make them more interesting. A character with an interesting personality but bland appearance can capture the imagination of readers. A visually-interesting but poorly-written character cannot. I've seen a lot of new writers make this mistake and it's a trap I've fallen into myself.

So personally, I would make your protagonist human unless there are some circumstances in the story that require them to be nonhuman. If you make them nonhuman without any good reasons (plot-driven or metaphor-driven) you run the risk of alienating your readers without any benefit.