Looks to the Moon (character)

"Big Sis" Moon (possibly a nickname she gave herself) is the iterator of the Looks to the Moon facility, which is a subregion of the Shoreline. Eating the neurons above her head will harm her, and will earn the "Stolen Enlightenment" achievement if you do so upon your first meeting. Eating all of Moon's neurons at any time will kill her.

Appearance
If you go the way the Overseer tells you to go from the beginning of the game, you find her sitting down and are not able to understand her. She is blue, with red wires protruding from her body and a red gem set in her forehead. Five white neuron flies float above her head. She sits on a pile of trash in a partially flooded square chamber, with sunlight coming through a hole in the ceiling. The chamber is reminiscent of a decayed version of Five Pebbles' chamber, and she is attached to the wall via mechanical arm.

About (Spoilers)
Moon's surrounding hardware is severely damaged and her processing power is reduced to the few neurons hovering above her. She reveals that much of her long-term memory is destroyed. If you have the mark granted to you by Five Pebbles, you will be able to understand her.

You are able to bring pearls, items and neurons to her; she will read pearls (which contain important lore to better understand what happened to the world's previous inhabitants) out loud to you if you've gained the communications ability from Five Pebbles and thanks you gratefully for bringing her Neurons, which are her only processing power at this stage.

When you give the first Neuron
"I am grateful—the relief is indescribable!"

"..."

"I could read a bit of Five Pebbles in this neuron before formatting it. His condition has severely deteriorated since last i heard of him. The frustration he feels is profound, and that angst has seeped into every part of him, every neuron."

"We were supposed to help everyone, you know. Everything. That was our purpose: a great gift to the lesser beings of the world. When facing our inability to do so, we all reacted differently. Many with madness."

"Some, out there, might still be trying. Communications have been bad for a long time, and by now i suspect most of us are isolated like me, or connected only in small groups."

"But even back when we were all more or less connected there were those who reacted to their task with anger. I can only imagine they are angrier now, alone in their cans, left only with their insatiable drive."

"But to be honest, i don't know how many of us are still alive at this point."

Moon talking to the Yellow Slugcat (The Monk)
"Your shape is familiar to me. I feel as if I... might have met your kind before."

"But my memory is so unreliable now."

"I see that someone has given you the gift of comunication. Must have been Five Pebbles, as you don't look you can travel very far..."

"He's sick, you know. Being corrupted from the inside by his own experiments. Maybe the all are by now who knows. We weren't designed to transcend and it drives us mad."

"Hm..."

"Such a familiar feeling."

Moon talking to the White Slugcat (The Survivor)
"Hello little creature"

"What are you? If I had my memories I would know..."

"Perhaps... I saw you before?"

"You must be very brave to have made it all the way here. But I'm sorry to say your journey here is in vain."

"As you can see. I have nothing for you. Not even my memories."

"Or did I say that already?"

"I see that someone has given you the gift of communication. Must have been Five Pebbles, as you don't look like you can travel very far..."

"He's sick, you know. Being corrupted from the inside by his own experiments. Maybe they all are by now, who knows. We weren't designed to trascend and it drives us mad."

"It is good to have someone to talk after all this time! The scavengers aren't exactly good listeners. They do bring me things though, occasionally..."

Moon talking to the Pink Slugcat (The Hunter) after having revived her with the Green Neuron Fly
"He... hello"

"Hello little... creature. You... you did this?"

"One moment. My memory isn't responding. I... I have no idea..."

"... must have been gone for..."

"..."

"Oh."

"Little creature..."

"You are not well."

"I am so sorry to say, but you do not have much time left."

"If things are as they seem... thank you."

"I don't know why you spent your... last... remaining cycles helping me. But know that i am deeply grateful. I have known very few beings who could aspire to such a noble thing. You are... an amazing little creature."

"I wish i could say i will always remember it."

"..."

"Little friend. Perhaps you already to know this, and i don't know what consolation it might bring, but..."

"You will wake right back up again."

Moon talking to the Pink Slugcat (The Hunter) after returning to the chamber
"Hi! Little saviour!"

"It is good to see you again."

"I wish I could help you like you have helped me... But like this, there is very little I can do."

"All I can do is express how thankful I am. You have given me some additional time... despite not having a lot of it yourself."

"I hope... this was meaningful for you."

"It was for me."

... when Moon likes you
"..."

"I think the rain is approaching."

"You better go, little friend! I will be fine. It's not pleasant, but I have been through it before."

... when Moon is neutral to you
"..."

"Rain... You better go. I will be fine."

... when Moon dislikes you
"The rain is coming. If you stay, you will drown. Now, leave me alone."

Items
Moon will tell you about some items you bring her. So far these are some items she will provide descriptions for:
 * Rock - "It's a rock. Thank you, I suppose, little creature."
 * Spear - "It's a piece of sharpened rebar... What is it you want to know? You seem proficient enough at using it."
 * Blue fruit - "It's the pupa of a bug! If you don't mind I'm a bit squeamish things like that, so would you eat it up already?"
 * Jellyfish - "This is a Jellyfish! Look out for its stingers."
 * Bubble Fruit - "It's a delicious plant. You should have it!"
 * Glowstone - "It appears to be... a pupa shell, smeared on the inside with a glowing substance? Perhaps the paste of some glowing insect? I honestly don't know."
 * Orange goo from Citadel - "This is a slime mold plasmodium. Thank you but I can't eat this."
 * Flashbang - "It's part of some kind of plant. The glowing is strange... I wouldn't look directly into it."
 * Vulture Mask - "I honestly can't tell what this is. It's light but strong... appears to be a composite material interwoven with bone. It could be part of an animal or purposed organism, but in my current state I'm unable to recognize it."
 * White mushroom - "Oh... Just don't eat too many of those."
 * Karma Flower - "This is a hallucinogenic plant. They used to call it a 'Wheel Flower'. It became the symbol for enlightenment, as it momentarily enables a creature to let go of its carnal self, and to contact the selves of other planes—dreams, memories, imagined worlds. Very long ago, they would eat these and stare into the fire."
 * Explosive Spear - “It's a weapon made with fire powder. Did the scavengers give this to you? Be very careful if you have to use it!"
 * Scavenger Bomb - "It's a lot of flammable powder stuffed into some kind of shell. I would be very careful around this!"
 * Smoke Bombs - "The flowering body of some fungus. It has high pressure built up inside—when it explodes the spores will spread everywhere."
 * Cherrybomb - "It's a branch of a fire bush—each of these nuts can explode. It's unpleasant rather than dangerous, except to your ears perhaps."
 * Overseer's eye - "It is the remains of an overseer. Overseers act as our eyes on the outside. I used to have a lot of them, but I lost contact with them when I was neutered. My umbilical is cut. So, since then I am not much more than what you are looking at—a little creature in a box. I suspect by now all my overseers are gone out there. Without me they would just roam around with no purpose. The scavengers tend to hunt them, it's one of their very few ways of expressing defiance. It's of course not completely impossible that there are a few left. Say hello if you see one."
 * Bubble Weed - "It's a plant that keeps pressurised air in these globules. I'm not very familiar with contemporary flora, so I can't tell you much more."

Trivia

 * Moon is still connected to the wall by her arm/umbilical, but the damaged hardware lacks power to let her move around.
 * From what she tells you it can be concluded that the water consumption of the iterators, and the water vapor they exhale, causes the heavy rains.
 * Moon is older than Five Pebbles. In the pearl records she talks about having seniority privilege. Perhaps this is why she calls herself Big Sis Moon in communications logs.
 * You can easily kill Moon by eating all her neurons. She would rather you didn't.
 * If you grab her neurons twice she will tell you to leave and will no longer talk to you.
 * It's possible to get her to like you again if you ate one of her neurons. But you will need to bring her enough neurons to replace the ones you ate, provided you at least left her with one.
 * Since Moon cannot leave her chamber, her room is flooded to the top every day when the rain comes.

Bugs

 * Bringing one or more Neuron Flies on your first visit earns you the Stolen Enlightenment achievement. This, however, does not negatively affect your relationship with her and is, in fact, the only way to get the achievement without ever hurting her.