OpenAI's system prompt bans goblins, raccoons, and other creatures due to a GPT-5.4 bug that made the model obsessed with goblins.

OpenAI's Codex system prompt contains an instruction: '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 ban was implemented as a fix in version 5.5 in response to a GPT-5.4 bug where the model developed a goblin obsession, with multiple Reddit threads documenting users whose ChatGPT could not stop bringing up gremlins.

The system prompt is visible in OpenAI's public repository at the cited GitHub link.