OpenAI has solved a “goblin mystery” impacting ChatGPT that caused the AI chatbot to become obsessed with the mythical creatures. Over the last six months, mentions of the word ‘goblin’ have shot up in ChatGPT, even in response to unrelated queries. The phenomenon prompted an investigation by OpenAI researchers, who found that the bug “crept in subtly” following the release of a new ChatGPT model last November . The new model was designed to be “smarter and more conversational” than its predecessors, featuring a variety of personality settings like ‘Nerdy’, ‘Candid’, and ‘Quirky’. Shortly after its release, ChatGPT users and researchers began noticing a pattern of repeated mentions of goblins, gremlins and other fantasy creatures. “Starting with GPT-5.1, our models began developing a strange habit: they increasingly mentioned goblins, gremlins, and other creatures in their metaphors,” OpenAI notes in a blog post about the issue. “We unknowingly gave particularly high rewards for metaphors with creatures.…