The nightmare stone first appeared in the video Crystal Funhouse where SuperMarioGlitchy3 set it as a trap underground so when SuperMarioGlitchy4 and some of his friends found it they all tocuhed it and got trapped in a nightmare controlled by SMG3. They later all escaped with the help of AustinDawgyDawg and GageDawg. The stone returned again in the blooper "Bowser and the Nightmare Stone" in which SMG3 sold the stone to Bowser so he can take revenge on Mario along with SMG4 and his friends again with a nightmare, but they escaped again and some nameless guy broke the stone with a pickaxe. It appeared one last time in the episode "SMG3's Plan to Destroy SMG4 because he felt like it", in which SMG3 used it to bring back a bunch of previously killed bad dudes.
Power and Abilities Edit
The Nightmare Stone has the ability to make anyone who touches it trapped in a nightmare, and if it's someone rubs it and takes control, they can trap anyone in a nightmare they desire with a strike of lightning. Also, it can apparently bring back anyone who is deceased. It also has a swtch whether the option is "Terrible", "Kirby Nightmare" and many more.