- "Hmm... let's see what you’ve found. Merlin’s Beard! It can't be — You can't have — This is extraordinary, beyond my wildest dreams! You've found Thaumatagoria! I always thought it was a myth! A story told to excite potion-makers, to make them dream impossible dreams! The rumours about its properties are legendary, you wonderful, wonderful young potioneer!"
- —Zygmunt Budge[src]
Thaumatagoria is a rare plant, believed to be a myth by even the Potioneer Zygmunt Budge. It is rumoured to be capable of legendary magics, but quite how legendary is unknown, due to its mythical status. However, it is known that it is a powerfully magical potion ingredient, most notably as one of the constituents of the Potion of All Potential.
Thaûma (θαῦμα) is Greek for "miracle" or "marvel". Thaumaturgy is a particular type of magic, originally referring to the miracles performed by saints.
- Wonderbook: Book of Potions (First appearance)