Some people spent Halloween dressed as their favorite movie characters. Others turned a chatbot’s usage limit into a costume.

Tech inspired some particularly specific Halloween posts this year, from oversized AI logos with error messages to a T-shirt referencing a cybersecurity incident. Even the couples’ costumes got the Silicon Valley treatment; many posted alongside the tagline “I hate SF Halloween,” followed by an explanation of a reference that probably wouldn’t land at every party.

Here are a few of the looks and jokes that caught our attention.

ChatGPT, with a water break before every answer

boo 👻

what are you dressed as for Halloween 🎃 pic.twitter.com/tHR4mLNiOf

— Pukerainbow 🤮🌈 (@pukerrainbrow) October 31, 2026

Ask a question, wait for an answer — and first, watch someone take a drink. These takes on a ChatGPT costume came with a running bit: the person playing the chatbot had to stop for water before responding. It’s a very clever dig at the water used to cool some of the data centers behind AI.

Some costumes also featured a fuzzy black-and-white logo with a message-limit warning, and a “Get Pro” button on the front. Even 2026 Halloween costumes are trying to sell an upgrade.

Claude, when the conversation ends early

just won scariest costume pic.twitter.com/64M6R8Jd4M

— Joseph Henry (@josephxhenry) November 1, 2026

ChatGPT wasn’t the only chatbot that got a costume. Anyone who has hit a chatbot’s usage limit mid-Claude task will get this version. In a post on X, user Joseph Henry also featured a “Daily limit reached” sign on his orange, furry Claude costume.

“just won scariest costume,” he wrote.

Creator Delia Lazarescu, who posts as @tech.unicorn, shared a similar look, crediting Claude for the “emotional damage.” Apparently, nothing ruins the mood quite like a chatbot telling someone to come back later.

A data center, obviously

Halloween costume. Maybe this’ll be the top for AI and data centers pic.twitter.com/EHrZBEwO5O

— Vanck (@vanckzhu) November 1, 2026

“dressed as the scariest thing I could think of…a data center!!!!!!” one Instagram user wrote, wearing a cardboard box with wires.

Given how much anxiety surrounds the AI boom, a data center makes a pretty timely Halloween choice. It also leaves plenty of room to stay in character by (also) demanding more water.

Alexandr Wang and Muse

I hate SF halloween, what do you mean you’re @alexandr_wang and @Muse pic.twitter.com/VImu5i1NcG

— alli (@sonofalli) November 1, 2026

Forget dressing as a celebrity couple. A post from @sonofalli offered a very Silicon Valley alternative — Alexandr Wang and Muse.

For anyone who hasn’t been following along, Wang is Meta’s chief AI officer, and Muse is the company’s personal AI agent. It’s the sort of pairing that makes sense at a tech party and probably needs a little explaining everywhere else.

A cybersecurity scare on a T-shirt

I hate SF Halloween, what do you mean your the eMudhra private keys from the hack? pic.twitter.com/8Pzro7Yngb

— Beff (e/acc) (@beffjezos) November 1, 2026

At first glance, this is just a black T-shirt with a big “4” on the back. The post from @beffjezos provides context: it references the compromised private keys used by the digital certificate provider eMudhra.

Cloudflare explained that the affected keys were so weak they could be recovered almost instantly from public certificates. The shirt frames its giant numeral with private-key text and lists other small numbers on the front.

Easy enough to wear. Slightly harder to explain over party music.

The jokes got even more specific

I hate SF Halloween, what do you mean you're the visualization of OpenAI’s solution to the Navier–Stokes Millennium Prize Problem pic.twitter.com/2xQSYIjywo

— Melissa Chen (@MsMelChen) November 1, 2026

And then there were the references that really required some homework. Melissa Chen shared an image of her friend dressing up as the visualization of OpenAI’s proposed Navier–Stokes solution, while @ElizaKosoy’s post referenced an AI escaping its sandbox in a Hugging Face incident.