The system prompt for OpenAI’s Codex CLI contains a perplexing and repeated warning for the most recent GPT model to “never talk about goblins, gremlins, raccoons, trolls, ogres, pigeons, or other animals or creatures unless it is absolutely and unambiguously relevant to the user’s query.”

The explicit operational warning was made public last week as part of the latest open source code for Codex CLI that OpenAI posted on GitHub. The prohibition is repeated twice in a 3,500-plus word set of “base instructions” for the recently released GPT-5.5, alongside more anodyne reminders not to “use emojis or em dashes unless explicitly instructed” and to “never use destructive commands like ‘git reset –hard’ or ‘git checkout –’ unless the user has clearly asked for that operation.”

Separate system prompt instructions for earlier models contained in the same JSON file do not contain the specific prohibition against mentioning goblins and other creatures, suggesting OpenAI is fighting a new problem that has popped up in its latest model release. Anecdotal evidence on social media shows some users complaining about GPT’s penchant for focusing on goblins in completely unrelated conversations in recent days.

OpenAI employee Nick Pash, who works on Codex, insists on social media that this “isn’t a marketing gimmick” to get people talking about GPT-5.5 and Codex. But that hasn’t stopped some OpenAI executives from leaning into the joke as word of the system prompt spread. “Feels like codex is having a ChatGPT moment. I meant a goblin moment, sorry,” OpenAI CEO Sam Altman wrote on social media Wednesday morning.