How to make an OC and NOT Mary Sue

Species

When choosing the species, make sure it belongs! As in, make sure that if it's an almost realistic world, don't make the OC a fantasy character!

Creepypasta OCs, here are a few species choices and my personal thoughts.

Nekos, absolutely NOT, they're not even scary!

Demons, very overused, but a good backstory can balance it out.

Angels, they're supposed to be good, but would be perfect for a "good" character.

Dark Angels, NO, that's basically a way of saying, "oh yes, a demon, but NO, make it an angel at the same time!"

Ghosts, NO, I don't care how evil they are, ghosts can't hold weapons and possessing isn't a valid killing method!

Animals, I have NOT seen many animal OCs, I would LOVE to see more!

Hybrids, NO, must I even explain why?

I could go on and on. Feel free to disagree if you want, but this is my opinion. Some species just aren't creative or scary at all. CREATIVITY IS GOOD!

Warriors OCs, my thoughts on these species.

Dogs, it's fine, but if you do, make a reason for cats to trust them.

Cats, must I even explain why this is the most logical choice?

Twolegs, absolutely NOT, if you do, make a reason for cats to understand them!

Any prey, NO, cats won't care if they can understand them, they'll hunt and eat them anyway!

Again, I could go on and on. Creativity, people!

Undertale OCs, yet again my thoughts on species.

Skeletons, NO, they're overused.

Dog-like creatures, ABSOLUTELY NOT, they're overused in CANON.

Cat-like creatures, a bit overused, but a good backstory can balance it out.

Humans, this is fine as long as they're not too much like Frisk or Chara.

Hybrids, the one time I'll say hybrids are fine as long as you don't mix too many things together, two at the MOST, I would say.

Again, I could rant for hours! Creativity!

Just follow this and you're good! Be creative!