‘Never Talk About Goblins’: OpenAI’s Instructions to Codex Have a Weirdly Emphatic No-Creatures Policy

A document posted by OpenAI on Github as part of the open-sourcing for Codex CLI, OpenAI’s most recent flagship coding agent, contains what looks like the entire system prompt for GPT-5.5 in a coding context. And it seems to correct for the model’s past addiction to talking about whimsical creatures both natural and supernatural. Here’s the relevant section (emphasis added): “provide the highest-signal context instead of describing everything exhaustively.\n- Tone of your final answer must match your personality.\n- 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.” Evidently this point is so important, the developers bring it up again a bit later: “For example, never use platitudes like \”I will do <this good thing> rather than <this obviously bad thing>\’, \’I will do <X>, not <Y>\’.\n- 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.” It’s not clear why this matters so much. If these were, for instance, canary words inserted into the syst