Prunsel is a surreal internet character that originated from a Tumblr post by user mr-gaurd-the-mummy in 2020. The user described a vivid dream where the character Sans from Undertale was replaced by a hyper-realistic, unblinking giant eyeball that spoke in ominous red text and emitted a low hum. The character's name, Prunsel, appeared in the credits of the dream-world game. Since its inception, Prunsel has become a fan-favorite cryptid within the Undertale community, appearing in fan art, mods, and creepypasta-style memes that lean into dream logic and psychological horror. It represents the weird, unsettling humor that characterizes modern niche internet fandoms.