The Moonstones, also known as the "Moon Stones", are seven magical stones that appear in the Lego series Monster Fighters. The stones are hidden in the Monster Realms and protected by monsters. If six Moon Stones are reunited, they will eclipse the sun forever and they will create a Night Eternal which is Lord Vampyre's goal.
Each Moonstone is a transparent object, with an encrusted symbol, or a liquid object. There are seven Moonstones, all of which are different colors. Lord Vampyre's Moonstone is encrusted with a bat, for example, and the Crazy Scientist's Moonstone is holding inside lightning strikes.
- The Moonstones are named after minerals of the same name.