Black Widow was a spider in Exclamation Point. She claimed to be the "femme fatale of all femme fatales". She wanted Alexander to marry her, so she could kill him. Part of the Riddle Book was stuck in her web, and Alexander was able to pick it up by unraveling part of her web.
This lady brings new meaning to the phrase "on the prowl". She loves to meet tender young men, and she always makes a deep impression on them. She's awfully proud of her web, even if she can't keep the wind from depositing mementos in it from time to time.