Developer simonw accidentally activated a "pet" in Codex Desktop — a small animated helper reminiscent of Clippy — and discovered that custom pets can be created. He built a custom character called "Pedalican": a pelican riding a bicycle, and documented the entire creation process with every generated image and assembled asset available in a GitHub repository.
What happened
Simonw says he missed the initial announcement (made "back in May") and later accidentally turned on the Codex Desktop pet. After learning that creating custom pets was possible, he specified a pelican-on-a-bicycle and let the system generate the graphical assets. The model GPT-5.6 Sol xhigh handled much of the work, and gpt-image-2 produced the sprite images over several iterations.
During the process he kept extensive notes and recorded intermediary steps. The repository contains every generated image, the combined sprite sheets, and GIFs for each animation loop — for example a file named waving.gif.
Technical details
- The character reference was produced as a single full-body sprite placed on a pure magenta (#FF00FF) chroma-key background to simplify cutout. The reference was designed to be compact, readable at 192×208 pixels, and easy to animate.
- Some GIF animations (such as waving.gif) were compiled from a single image generated by gpt-image-2.
- The prompts used to create the initial character reference and subsequent images are documented and included in the repository, showing the structure of the prompts and the steps taken.
Open-source components
Key implementation details are open source and available under the Apache 2.0 license. In particular, two skills are noted:
- hatch-pet (from openai/skills)
- imagegen (from openai/codex)
These components were used alongside GPT-5.6 Sol xhigh to generate the images and assemble the sprite assets.
Name and context
GPT-5.6 Sol coined the name "Pedalican," which the author reports liking. The project demonstrates a practical example of using text-to-image generation to create simple, game-ready sprites for desktop or game use, and the published materials provide a step-by-step reference for others wishing to reproduce or adapt the workflow.
