What did rumpelstiltskin do?

Rumpelstiltskin is the name of a German fairytale and also the name of the main villain of said tale. The story tells us about a poor woman whose father convince the king she is able to turn straw into gold, the king then tries to force the woman to do her magic if she wants to preserve her life. When the poor woman is turning desperate, a magic elf-like creature appears and promise her to use his magic in exchange of something very precious, her first-born child. The king is so happy for her accomplishment, he decides to marry her. The problem arises when she has a baby and the elf appears again, wanting to make her fulfill her promise. The woman pleas for mercy and the creature gives her a chance, she has to guess its name in order to be set free of the promise. The task seemed impossible, but after several failed attempts, she is lucky because one of her servants had overheard the creature dancing and singing a song in which he reveals his name: Rumpelstiltskin. The next time the creature appears, she tells him his name and he is so angry he runs away to never come back, leaving the woman to life her life happily with her husband and baby forever.