Talking about a character whom your POV character does not know by name yet

So I know the character's name already. I don't need a placeholder for me. I need a placeholder for my protagonist, who hasn't been properly introduced yet, you know, besides just calling him "the man." However, they are in a full scene together before learning names. I did a bit of research and read somewhere that it's often good to take a characteristic of theirs that is prominent and give them a nickname based on that. I've settled on the nickname "Ink" for now, in reference to how heavily tattooed the guy is, but if I'm being honest, I hate this convention. While I'm aware that some other people nickname people in their heads if they don't know their real name, it's just a weird concept to me. Anyone got advice?

Yeah, idk if this is the best example from the passage but I'm extremely shy about my writing and this is all I feel okay sharing for now:
“Hey, hey… Can you hear me?”
The man slowly nodded. He tried to say something, but just shrunk down in a series of coughs. He turned on his side and coughed up something tinged black in color.
Aurelius bit down on his lip as he looked him up and down. The burns were bad enough, but he also had what looked like a sword slash across his chest, as well as various cuts and bruises everywhere. Perhaps it looked worse than it was, as he had tattoos all over his body, and it was hard to tell what portions of skin were actually intact. There was just ink everywhere. Just Ink…
Fiera too was on her knees next to him. She helped him roll on his side to keep him from potentially choking.
(…little skip of some dialogue here so you don't have to read more that doesn't give you an idea of what I'm talking about…)
Moreau, Septima, and Fiera all worked to carry him to the rocky shore where they helped him sit up.
Aurelius pulled out his waterskin and held it near Ink’s lips. He took a few ravenous sips, gasping a bit between each gulp of water. After he finished, he started coughing again, but sitting upright, it wasn’t quite as bad as before. Aurelius took a scrap piece of cloth from his bag, wet it in the creek, and started dabbing his forehead and neck to cool him off.
(Also for additional context, it's 3rd person limited to Aurelius during this chapter)

Okay, thank you! I think that's the #1 most distinguishing feature (as he is absolutely covered), so it's likely the thing someone would notice first.

Other example: my roommate saw a really cute girl but didn't know her name. She had a distinctively long face, so she said she called this girl "horseface" in her head, but not in a mean way lol. So I'm well aware that other people do it, I just have a hard time generating them myself because it's not a natural train of thought for me, I guess.

Not really, it's just weird trying to replicate it when you know it's something a lot of people do but you don't. For me it was mainly the question of: does this sound natural?

Yes, that's the kind of perspective I was hoping to get, so thank you! And maybe? I'd be more comfortable over PM for sure. I'm also at 33K words of a rough draft, so it's kind of a lot and also, well, rough.

Thanks! I'll consider it. Though I'd probably just give a little at a time as I'm comfortable, because as I said, I'm really shy about my stories. You've definitely got a taste of some of my characters through RP at least, though.

Ooh, fun. I'd definitely be interested in exchanging stories sometime.
And yeah, RP is a great way to piece together characters. I even have one case where I made up a character for an RP and he ended up so fleshed out, and I loved him so much that he became part of my story, which has a completely different setting.

Yeah, it definitely helps the process.

Would you like me to go ahead and send you my first chapter? I feel pretty good about it, with the exception of a few edits that need to be made later.

More the latter, but if you see anything glaringly obvious, I don't mind constructive criticism here and there. I mostly write for myself and don't plan to publish, so editing isn't something I do a ton of.

Okay, cool! I'll critique where I can (but I also tend to be nice but honest, so don't worry about me brutalizing anything lol).

(Oof, yeah. That's valid. You don't have to worry about that with me at least, because I'm terrified of hurting other people's feelings.)