What is the name of the sorceress who wants Scrooge's first dime?

The sorceress who wants Scrooge’s first dime is Magica De Spell.

Magica is a witch from the Scrooge McDuck comic universe, created by Carl Barks. She first appeared in “The Midas Touch,” published in 1961. Her recurring target is Scrooge’s Number One Dime, the first coin he ever earned.

Magica wants to melt the dime in the fires of Mount Vesuvius and transform it into a magical amulet capable of granting the Midas Touch. A common mix-up is assuming she wants the coin simply because it is lucky; Magica instead believes Scrooge’s wealth gives the dime its magical value.

She is associated with Naples, Italy, and has appeared in comics, DuckTales, video games, and other Disney productions. Her name is sometimes localized differently in translated editions, but “Magica De Spell” is the standard English answer.