Mafurako is a returning character from the original game. She first appears in Block World, where you must find her six times before she will open the door to Snow Valley. Interacting with the black totem will give you a hint to her current location.
In Snow Valley, Mafurako can be found randomly walking around. Interact with her to receive the Scarf and Hat effect. If you already have it, she will wake you up instead.