Sprunki is a fan-made mod of the music game Incredibox, created by NyankoBfLol and first shared in 2024, where players drag icons onto characters to build a loop. Tunner quickly became a fan favourite among its cast. Mustard is one of the many themed fan variants that recolour and remix the cast while keeping the core loops. Clips of individual characters like Tunner spread through YouTube, TikTok and soundboards because fans isolate them to rebuild mixes, learn each part, and reuse them in edits.