The Chocobo is a large, (usually) flightless bird from the Final Fantasy series that comes in many colors, famously yellow. I drew this Super Mario World-styled as a Yoshi replacement - it replaces Yoshi eggs and Yoshi-related signage as well. It does not require a custom palette. The hex edit needed to fix the lower half of the overworld sprite's palette is included for convenience, but can also be referenced in the ROM map. The tail feathers aren't so large and upright like much of the source series's material, but since this is within Yoshi's native framework, I'm not sure I can pull that off except with the credit Yoshies.
Anyone is welcome to expand or improve upon it and submit updates or variants without my permission.