Some headcannon about zalgo?
Zalgo headcanons? Zalgo headcanons! I̡̤̞̱͈̋ͥ̔̈'̽̎̂̂͐m͎͇͇̘͎̠ ̺͓̦͉̟͖͢s͖̬̱̱͖̖̳o ͤ̒͛g̮ͥla͇͈͖̎ͨ͋͝dͭ̎̏̍ ̵̍ͫ̍yŏ̖̭̘̠͓̺̿̆ͯ̽ͣu ̧̅͆ͯ̑͆ͮas̗̰ͦ̓k̶ͥed̺̹̳̤̦̜!ͥͦ̂ Here, have a few from my little... alternate universe or whatever.
The less you know, the safer you are. The second you hear of him, even in passing, it's over. You'll start to notice things that seem odd once in a great while. They'll be few and far bet ween, but every time it happens, that's a bit more exposure to Zalgo. The same goes with mentioning him, or even thinking of it.
He doesn't necessarily directly influence humans himself, but rather the world around them. Just because he finds it amusing. The corruption of biological life is just a side effect of his actions, but he doesn't really care and if anything uses that to his advantage, spreading more chaos and carnage in his wake.
If someone or something were to become Zalgofied, it's actually a quite slow process as it's usually the result of cumulative exposure to the corruption. It's like… One would go from being relatively unaffected and only noticing a weird drawing or two or some corrupted text, to seeing it more often and thinking "Heh, Zalgo" and being a bit confused after the fact, to… full-scale something being noticeably wrong. Only after that point is when the physical effects start to set in, such as the blackening of eyes, warping of flesh, etc. Eventually, you b̶ec̵om̵e̵ o̴̓n̸̮̈́e ̶͍̳͗̋w̸̛i̴̙̤̽t̷͉̓͒ͅh̷͈̀ ̷̫̑t̷̕͝ͅh̴̡͝͝ȇ̸ ̷̭̠͐H̵̞͐̎ï̵̗̯ṽ̴̰͛ë̴̺́́ ̵̼̼͂̃M̶̜̒ĩ̵̱̚ņ̵̣̈́̐d̶͉̈́͐.̵̻̿
If he were to take on a human form, it wouldn't seem... Correct. There would be some major unplaceable uncanny valley energy, despite looking and seeming completely normal. He'd wear either a t-shirt and sweatpants and not give a shit, or the fanciest, nicest looking suit he could. There'd be no in-between. He also speaks every language, except he has a completely different voice for each language as well. Each different voice used to belong to something or someone that became part of the Hive Mind.
He doesn't need a Costco membership card. He'd just be able to go in if he felt like it, convincing the workers due to funny mind control that he DOES have one, despite clearly not having one.
Zalgo defies the laws of physics, holding quite literally a dead star / black hole. Somehow, he is completely unaffected by it. He's everywhere, yet nowhere. Just some eldritch, cosmic entity.
He also resides in some alternate dimension beyond our known universe. Despite this, he is able to see and interact with everything, the "glass" walls of his realm acting as a touch-screen window to anywhere, should he choose to do something.
He once corrupted an entire planet lightyears away from Earth. It ended up in a similar state to the planet TrES-2b, except it constantly emits a radio signal that if tuned into sounds like the agonized screams of the damned. Not much else is known about it though, as the scientists who discovered this began to experience the symptoms of an unknown illness, their ears bleeding, and starting to ramble on in seemingly gibberish. Only a few of them were able to remain coherent enough to report their findings, although shortly after they too fell strangely ill.
This is a silly one, but strangely enough, pizza rolls in a large enough quantity can be used as an offering to buy yourself just a bit more time. For reasons only known to him, he likes them.
Another silly one, but he thinks that human souls taste exactly like marshmallows when consumed.
I don't typically write out my headcanons so I'm not entirely sure what to share, but it'̧̹s̰̥ͅ ͛͆͏n̐̽i̗͖ce͡ ̩̘̃͗h̖̤ͯ͆a͜v̟̐i͚̱ͣ̽n̐̽g̐̈́ͫ͏ a ̅re̮͖͓͑̑̈́͢ả̽͏̻͓sͅo̤͈͡n̎ ̇tö͎̱́̈́̈́͜ sh͇ͣ̾a͕̍ͭ̃́ṙ͍eͩ͗̓ ̰̰t̼̱̻̑̏̀ȟͯe̗̱̹̓ͩ͂m̱͔͔͒̏̉͢!͉͈̑̃