A guy burns his foot, so his “teacher(?)” has him dip it in pancake batter or something and then put the coated foot in the snow. Another kid somehow had his whole body covered and falls into the snow. They find that the boy who is entirely covered has vanished. Similarly, the boy discovers, to his horror upon peeling back the now rubbery batter, that his own foot is gone, replaced with bone and covered with the yellowy-white material instead. It’s like a boot, complete with treading on the bottom