Kirby's Adventure / Kirby: Nightmare in Dream LandEdit
In Kirby's Adventure and Kirby: Nightmare in Dream Land, Nightmare wanted to give the people of Dream Land nightmares. To prevent this, King Dedede broke the Star Rod into several pieces. Kirby though that Dedede had bad intentions, so he beat his minions (and eventually Dedede himself) to reunite the pieces of the broken Star Rod. Doing this summons Nightmare, who you must battle with the Star Rod.
His name is mentioned as Nightmare or NME. He is the founder of Nightmare Enterprises, a company that sells Demon Beasts to people who would buy them. Customer Service sells these monsters to King Dedede, as they are both determined to get rid of Kirby.