However, it is used in the book.
Here's why you can't get it in the game and how it's used in the book:
* Game limitations: The game focuses on a limited set of potions for gameplay reasons. Wiggenweld is a relatively basic potion, and including it might have been considered unnecessary.
* Book purpose: In the book, the Wiggenweld Potion is significant because it is a potion that Harry learns to brew from Snape's old potions book, showing a shift in Harry's skills and understanding of potions. It's not directly used for major plot points, but it represents Harry's growth as a potioneer.
So, while you can't brew or find Wiggenweld in the game, it plays a significant role in the book as a symbol of Harry's progress.