They say that if you look at him in the eyes, he'll come back when you're sleeping and braid your hair. When you wake up your hair would be braided and filled with lice. He'll as well look through little boys under wear drawer and take them.
My godmother was telling me how she saw one in Guatemala and she didn't look at it but it still went up to her and ran away and then later that night she woke up with braided hair but a very messy braid. She saw it later the night from a distance and looked at her, then later the night she kept hearing noises in her room and after that she never saw it again, but she found a small cloth in her room that was wet and all dirty. She still has it because she believes it's good luck and it'll keep it away. She thinks it was part of the duendes clothes.