The Protagonist

is a Hearthian whom the player controls. Like most Hearthians, they seem to have an affinity for toasted marshmallows and sap wine. They are adolescent, the newest cadet in the Outer Wilds Ventures ranks. Their name is never specified, and they are usually affectionately referred to as "Hatchling", or some other descriptive term or pronoun.

Due to the nature of this character being decided by the player's actions and attitude, this page will describe them based on the extrapolation of all of the choices the player could take. In other words, this is a description of the "ideal" Protagonist. Most of this information is taken from the 'Self' paradox ending, which provides the most exposition by themselves. A full transcript of this exposition is at the bottom of the article.

Without EVA
As with most Hearthians, they have four large eyes, wide notched ears, and three nailed digits per hand. Their clothes, typical for Hearthians, are primitive, scruffy and roughly stitched together. Their sleeves are rolled up, and they wear outdoor socks into which their legwear is tucked. Despite being mentioned as having an inauspicious academic career, they seem to be free of any injuries, unlike Gossan.

They are the only Hearthian to be seen both in and out of their EVA suits.

With EVA
No two Outer Wilds EVA suits are the same. 's suit consists of a helmet with a large opaque gold-filmed visor, a baggy - possibly burlap - outer layer and thick rubber gloves, a reinforced belt, and large, rugged laced-up boots. Pressure seals are apparently maintained by straps, belts, and what appears to be a poncho around the chin, neck, and shoulders. The belt holds a small pocket-book and a reel of suture, presumably for tending to ruptures in the clothes. On the back is an RCS jetpack, a rucksack and bedroll - much like those worn by mountaineers - with racks for a Signalscope and Scout Launcher.

This iteration of the EVA suit apparently does not include legwear - preferring to keep the torso and head pressurised and ventilated.

Helmet telemetry
Being the primary means of ascertaining the status of the astronaut and the universe around them, the helmet is loaded with a great deal of telemetric data. It includes:
 * Meters for oxygen, fuel, and available extra-thrust.
 * The current force of gravity acting upon them (relative to Timber Hearth)
 * Thrust vector
 * Physical wellbeing
 * Global position
 * The Scout's last photograph
 * Data from the Signalscope
 * Various environmental heads-up messages and warnings (such as Ghost Matter proximity, RCS fuel exhaustion, or suit ruptures).

History
The game begins on the day of 's first solo launch, before which they accidentally and unknowingly pair with the Nomai statue in the Observatory, causing them to be aware of the ongoing time loop. The game (and each loop thereafter) begins with them waking up in front of a campfire, roused by a mysterious flash surrounding the Giant's Deep gas giant.

They seem to have had a part in the destruction of one of Gossan's eyes, or at least have borne witness to the incident.

Personality
As is a surrogate for the player, most of their personality is derived from the choices the player makes in what they do and how (and if) they speak to others. What is definitely known is that they are possessed of great sardonicism and gallows humor. Initially anxious of their mission (and distressed of the repeated cataclysm), they cope by seeing their cyclical day as choresome, and in one scenario, they wonder morbidly what it would be like to cause a paradox. They are generally patient and well-composed - if resigned - and curious of the universe around them (if only to attempt to stop it from exploding or fizzling out). They are affable and concerned for the wellbeing of their fellows. However, they eschew safety as a concept of importance, perhaps due to their foresight and functional immortality. While patient, they are willing to forego procedure if they are able (such as using the Launch Codes before formally receiving them from Hornfels). They can be braggadocious. Their sense of organization is fastidious, able to create a detailed organigram on their ship's computer to lay out what they have learned to extrapolate what they haven't.

They are, unsurprisingly, terrified of anglerfish. They can also be whipped-up into a panic; when confronted by themself, one possible exchange can involve wild flailing and hysterical screaming.

Abilities
As a Hearthian, they are ordinary, and most of their abilities come from their EVA pack and their equipment. The main conceit of the game is their unwitting pairing to the Nomai sculpture at Hornfels' Observatory. As such, they are precognitive of the impending destruction of the solar system. When they die, their memories are sent into the past and bequeathed to them as they sleep in front of the campfire. They seem to possess a sizeable technical aptitude, able to operate devices of both Hearthian and Nomai construction. They have a great (possibly eidetic) memory, and can recall information to interrogate others or update the Ship Log on a subsequent loop if they are unable to reach it before their demise (although this is probably for the sake of gameplay convenience).

They are able to learn how to meditate and fall into a peaceful sleep, even in the face of imminent (or excruciating) demise, such as being crushed, asphyxiated, impaled, cooked, vaporised by Ghost Matter, or by the eponymous apocalypse. They cannot swim. Their practical mastery of aviation is dependent on that of the player's, but is historically poor, as on their inaugural jetpack launch, they had become stuck in a crater at Timber Hearth's south pole. They are not shown to possess any musical talent or affinity, though it could be argued by the Ending that they are at least an adequate conductor.

Intended Ending
Armed with the knowledge that there is a warp-capable spaceship nearby and an Advanced Warp Core, they use the Vessel to travel to the Eye of the Universe, fall into it, and emerge in a post-mortem facsimile of Hornfels' Observatory, where they learn about the demise of the Nomai and Hearthian civilisations and the heat death of the universe. They gather together quantum versions of the other Hearthian travellers (and Solanum, if they've met her), and instruct them to play music around the campfire one last time. They leap into the anomaly presented to them, and are consumed by the expanding nuclear fireball of the Big Bang.

If they had become separated from their Little Scout on the Eye (such as by launching it into the maelstrom), it is seen in the sky 14.3 billion years later.

First Loop
Due to how many times the conversation branches, transcribing it could easily become an exercise in recursive futility. This dialogue tree has been constructed in such a way that significant parts of a response may be a link. Clicking it will scroll the browser to that content to continue reading.
 * ...Whoa.
 * >What the heck happened?
 * If you're me, then I'm just as confused as you are.
 * >Do you think we have the same memories?
 * Good question. Let's see...
 * >Do you think it's okay there's two of us?
 * Well, we're talking to each other and nothing's exploded yet.
 * >Yeah, it's a pretty novel experience.
 * Right? It's kind of nice!
 * >Gossan always says that means the date's going well.
 * Yeah, but it's Slate's definition of a boring date. Makes sense Gossan and Slate never dated.
 * > That and the whole mishap with Gossan's eye. 
 * Oof. Yes. The eye thing. Yeah, that's... yeah.
 * >Yep./Sure is.
 * Uh huh.
 * >I very much do not want to discuss that.
 * Nor do I. Hasty segue?
 * >Hasty segue.
 * So hey, what do you think happens if you don't jump into the black hole again at the end of this loop?
 * >Huh. That's a good question.
 * It's something I've been wondering about. We're in thoroughly uncharted territory at this point.
 * >Unlike all the other time manipulation we've experienced.
 * Are you being sassy? You can't sass me! You are me! Does kind of prove we're the same person, though.
 * >Truly, we are the Feldspar of weird time stuff.
 * Oh geez, Feldspar would just use the time loop to try increasingly outlandish stunts, wouldn't they. Might be a good thing they aren't aware of it.
 * >If I don't, then where did you come from?
 * That's a good point. I mean, I feel as real as ever, so I don't think I'm a figment of your imagination or anything like that.
 * >That's just what a figment of my imagination would say!
 * Are you being sassy? You can't sass me! You are me! Does kind of prove we're the same person, though.
 * >I'm no expert, but you seem pretty real to me.
 * Thanks. You seem real to me, too, so... I guess there's just two of us now!
 * >Guess we'll find out!
 * I guess so!
 * >Maybe the universe doesn't mind two of us.
 * Hopefully not. Besides, an extra version of us is definitely better than if we'd created an extra anglerfish or something.
 * >GEH.
 * My thoughts exactly.
 * >That's setting the bar pretty low.
 * That's not just setting the bar low, that's setting it at tripping height.
 * >Agreed. We're charming and have fewer teeth.
 * That probably counts for something.
 * >This is the greatest day of my life!
 * Sure, two of us is great and all, but is it the greatest? What about the day we, you know... what about that one?
 * >Are you talking about the day I...?
 * What? No! No, I'm talking about the other one.
 * >OH. Yep, that makes way more sense.
 * Yeah, now you've got it. That was an incredible day. But today is probably the next greatest day of our life after that one.
 * >Wait, can you read my mind?
 * Definitely no. I just have the same memories as you. ...Except for this loop, I mean. I started this loop by popping out of a white hole inside the Ash Twin Project, since in the loop before this one I jumped into the black hole. So what do you think happens if you don't jump into the black hole again at the end of this loop?
 * >What other memories do you have?
 * Let's see... We should have all the same memories before the whole "going into space and becoming aware of the alien time loop" thing.
 * >Think it's okay there are two of us?
 * Well, we're talking to each other and nothing's exploded yet.
 * >Oh, right. That one's probably still the greatest.
 * Haha, I know, right? But today is probably the next greatest day of our life after that one.
 * >Are you me from the last loop?
 * I think so. I started this current loop by popping out of a white hole inside the Ash Twin Project.
 * >I started at the campfire like usual.
 * Makes sense to me, seeing how jumping into the black hole is definitely what created two of us. So, what do you think happens if you don't jump into the black hole again at the end of this loop?
 * >What do you remember from before this loop?
 * I remember all the time loops, including last loop when I jumped into the black hole in here. What about you?
 * >Me, too. Sounds like our memories diverge at the start of this loop.
 * Makes sense to me., seeing how jumping into the black hole is definitely what created two of us. So, what do you think happens if you don't jump into the black hole again at the end of this loop?
 * >Same, except I woke up at the campfire, like always.
 * It makes sense one of the two versions of us would start at the campfire as usual. So, what do you think happens if you don't jump into the black hole again at the end of this loop?
 * >This got weird in a hurry.
 * Yeah, duplicating living beings probably wasn't what the Nomai had in mind when they built the Ash Twin Project.
 * >I wonder if we have the same memories.
 * Good question. Let's see...
 * >I wonder if there being two of us screws anything up.
 * Well, we're talking to each other and nothing's exploded yet.
 * >AAAAAAAAAAHHHH! (From here on, Future Self gesticulates wildly.)
 * What have we done?! Jumping into that black hole was a terrible idea!
 * >Yes. Yes, it was.
 * ...Whoa. (Conversation restarts)
 * >I needed to know what would happen.
 * ...Okay. Okay, I'm calm. (Conversation restarts)
 * >AAAAAAAAAAAAHHH!
 * AAAAAAAAAAAAHHH!
 * >Just needed to get that out of my system.
 * AAAAAAAAHHHhhhokay, I'm done screaming, too. (Conversation restarts)
 * >AAAAAAAAAAAAAAAHHH!
 * AAAAAAAAAAAAAAAHHH! AAAAAAAAAAAAAAAAAAAHHH!
 * >AAAAAaaaAAAAAaAAaaaaaHHH!
 * AAAAAaaaAAAAAaAAaaaaaAAAHHH!
 * >AAAAAAAAAAAAAAAAAUGHHHH!
 * AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAHHHHHHH!!
 * >AAAAAAaaah... hhh... ha.
 * AAAAAAAHHHhhh... (pant, pant)...
 * >You good?
 * ...I'm good. (Conversation restarts)
 * >...AAAAAAH! AAAAAAAAAAAAAHHH!!
 * AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAHHHHHHH!!
 * >WAAAAAAAAAAAUUUUUUUUUUGH!
 * WAAAAAAAAAAAAAAAAAUUUUUUUUUUGH!
 * >WAAAAAAAAAAAAAAURGLHHH!
 * AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAHHHHHHH!!
 * >AAAAAAaaah... hhh... ha.
 * AAAAAAAHHHhhh... (pant, pant)...

Second paradox loop or later

 * "Hey, me."
 * >Remember leaving on our first solo trip?
 * "Yeah! That feels like ages ago. We'd have died that first time out if the time loop didn't exist, though. Isn't that weird to think about?"
 * >Weirder than there being two of us now?
 * "Wow, I guess I AM pretty sarcastic."
 * (If made Tuff too sick) "Tuff was right - I AM the worst."
 * >We were disasterously unprepared for space.
 * "It's unsettling to think about. Especially when you remember even Riebeck survived their first launch."
 * >(If flew manually to the Sun Station) Remember landing our ship on the Sun Station?
 * "YES. I can’t believe no one was around to see that. We’re probably the best pilot in the space program by now."
 * >Yeah, but we’ve also died more than anyone else.
 * "That’s true.  I’m not sure how to factor that in."
 * >Not that anyone else knows it.
 * "Still, it’s kind of nice to get to say it out loud. Even if it’s just to ourself."
 * >I needed to brag about that to someone a little.
 * "That’s fine. It’s kind of nice to hear it said out loud."
 * >Did that technically happen, with how the time loop works?
 * "What? ...Oh, come on, don’t take that away from us!"
 * >Just kidding, I don't care how time works.
 * "Haha, yeah, me either.  ...Obviously."
 * >But given it only happened in a previous loop...
 * "The worst part is we’re the same person, and you know I’m going to agree with you. (Sigh...)"