He captured Lolo in a dream world, keeping her in a bubble. While posing as the real Klonoa to taunt the crying girl and lie to her that he (the real Klonoa) won't return because nobody cared for her. Nightmare Klonoa was then confronted by his real counterpart, being shocked to see him and fought with him. After a battle with them shooting their respective Wind Bullets at one another, Klonoa successfully inflated his evil alter ego, temporarily immobolizing him.
When the nightmare began to crumble around them, Klonoa and his friends were teleported out to safety by Lolo waking up, leaving the inflated Nightmare Klonoa behind in the realm. Eventually, he became free from the effects of the Wind Bullet, and was dismayed that the heroes left without him. Nightmare Klonoa was then contacted by a mysterious voice, who offered to help him see Klonoa and his friends again.
- Nightmare Klonoa is never mentioned by name in the webcomic. His name was only known when it was confirmed by Jim Zub on Twitter in response to a fan.
- When asked if Nightmare Klonoa was inspired by a scrapped doppelgänger character from Door To Phantomile, Jim Zub stated that he didn't intend it himself, but that "Ariga may have been channeling that". 
- Nightmare Klonoa's cap depicts a ghost chasing a smaller Pac-Man. This is most likely due to Nightmare Klonoa's villainous nature as the ghosts are usually shown as the main antagonists of the Pac-Man franchise.
- Unlike his counterpart, he shows no concern for Lolo.