@@little_bonely found that Low Quality Swap Sans has a bigger hitbox when you're moving than the rig does. As his feet are sticking out so much when he walks. (Still better to use it, though-)
Hey, sorry for a suddenly excessive late response, but it's Papyrus Encounter by Thanatos. Here's the link for you. ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-eXBG9zpc1PE.html