Hal

The context is that when Liquid falls over and dies from Foxdie, he actually just passed out from the symptoms but lives. He was brought into a lab for testing where they discovered he's still alive and so kept him there to performing variable tests on him until Philanthropy needed to fake Snavid's dead where the learn that he is alive and the save him and he (reluctantly) joins them

Headcanons!!

Missing skin on face (wanted tissue for testing)

Missing fangs (he was very violent and kept trying to bite) (ties into the headcanon I have that the snake clones have sharp, snake-like fangs instead of canines)

Missing arm (thanks a lot Ocelot)

Heart palpitations (from foxdie)

Eye injury (smth like strabinus (eye misalighnment) or ophthalmoplegia (eye paralysis)

Hates how labels feel on his clothes (relatable)

C-PTSD, BPD, and Autism

At first he was avoidant, very angry, and probably almost got kicked out 100000x by David

This guy can survive basically anything (I mean c’mon… he survived a Hind-D exploding, a Metal Gear exploding, AND falling from a large height just to mention a few)

Misses Psycho Mantis (yeah he didn't survive shadow moses, David does feel guilty about separating them)

Has Snake-like pupils when focussing in on something (yet again, ties into the headcanon I have that the clones have snake-like features)

Emergency backup - stays with Otacon to make sure he is safe and will help Snavid out if in trouble

Casual crazy lore drops about his childhood

Will eat anything given to him (will complain but he’ll eat it)

He will eat anything given to him. Would he be a bit cautious? Maybe. But fellow FOXHOUND members would happily give him their leftovers from their meal and any pieces they don't want and Solid Snake would gratefully accept them

Because of this, however, he has gained a stomach of steel. It's hard to make him feel ill due to food

He adored Gray Fox, often seeing him as a role model and almost like a brother (which is why the betrayal and death hurt so much)

Kaz would sometimes cook for Solid Snake since he felt guilty for using him as a means to an end to get revenge. Solid Snake didn't know this and thought it was just because he performed well in training

Into 70s/ 80s rock music

Hasn't kept in contact with anyone. Especially not after the events of MG2. He wanted to be left alone and undisturbed without anyone bothering

Never talked much outside of missions and training. He'd respond/ start a conversation when he needed to and not anytime else

Following that up. His answers would always be very direct and to the point. Never expanded more than he had to and social expectations for conversations eluded him (such as asking the person back how their day went)

Socially awkward. Due to his direct speech it left little room for chat so every discussion went silent quickly with the other person trying to excuse themselves quickly. Not to say he doesn't suddenly gain every skill imaginable when he flirts with someone. Somehow he's amazing at that

Massive soft spot for animals, especially dogs. If you asked him whether he would save you or a dog he'd give a long pause and would have to debate it for a good couple of seconds

How he sleeps is the world's greatest mystery. If he knows he isn't in a dangerous location, he will sleep like a log and you'd have to practically shove him out of bed in order to wake him up. However, if he is in a dangerous area, he is an extremely light sleeper and is always alert. Furthermore, he will sleep anywhere and in any position. He may not enjoy it but if he can fit in there then he can sleep in there

Adding onto that, Kaz has found him sleeping in a carboard box before

Kaz was very rough on him in training. There were obvious reasons such as he was in FOXHOUND and so had to be at the top of his game and Snake also had to be good enough to take down Big Boss but there was almost a sense of justice for Kaz. The son who looked like the man Kaz hated was under his command and had to follow his every order. He could push the son as far as he wanted and Snake couldn't complain one bit

Has a tiny sketchbook and pencil he likes to bring during long missions before joining FOXHOUND. It would give him something to do whilst he camped out waiting for his next order. This habit became something he would just do in his room after he was recruited into FOXHOUND since he didn't have much time when on a mission

Pre-MG1, he loved watching military movies and criticising how inaccurate they are to real life