Nightmarens are the residents of Nightmare and creations of Wizeman. As such, they are generally accepted to be evil, with the notable exception of NiGHTS. It should be noted that all nightmarens are genderless.
Level One Nightmaren
Level one is the highest rank for a Nightmaren. The level one Nightmarens are NiGHTS and Reala. They were created to be Wizeman's right-hand men.
Level Two Nightmaren
The second level nightmarens are Jackle, Clawz, Gillwing, Puffy, Gulpo, Donbalon, Girania, Chamelan, Bomamba, Cerberus and Queen Bella. Second Level nightmaren (with the exception of Reala And Wizeman) are essentially the Bosses of the games.
Level Three Nightmaren
These are all the minor nightmaren creatures that appear throughout the gameplay, from Mamus to Gaos. Due to being lower-ranked, they are easily dispatched by NiGHTS by Paralooping, Drill Attack, or Touch Dash. They usually serve as obstacles.
They are also known to actually chase and eat Nightopians in Journey of Dreams. 3rd-level Nightmarens are capable of easily beaten if Helen/William toss Blue Chips at them.
HistoryNightmaren are the product of Wizeman the Wicked, created from his own twisted ideas. They serve the purpose of stealing Ideya and destroying Nightopia, plunging it into pure Nightmare. There are three Classification of Nightmaren with their own purposes.
Common Nightmaren, Third Levels, steal all of the Ideya except for the red ones.
Second Level Nightmaren are the "bosses". They are more intelligent then Third Levels and are placed in Visitor's dreams to hold the collected Ideya and stop anyone who tries to take them as well as control the Nightmaren in that dream. They are capable of creating their own worlds, which the player is drawn into after freeing NiGHTS to fight them, possibly indicating they are also tasked with making sure NiGHTS does not go free.
The First Level Nightmarens, only two seem to exist, NiGHTS and Reala are the most powerful of Nightmaren. Created to be the commanders of all other Nightmaren and Wizeman's "right hand men" they are the only Nightmaren capable of stealing Red Ideya from Visitors, a rare occurance.
In Journey of Dreams, Third Level Nightmarens steal Ideya through nightmares, warping dreams into horrors and forcing Visitors to abandon them, but against NiGHTS they don't stand much chance. Second Level Nightmarens are fought twice: once to force their retreat and the second to defeat them and claim the Ideya they hold. First Level Nightmaren, Reala being the only one left in command, control or lead the other Nightmaren when needed and preform important tasks like stealing the rare red Ideya, or in this case, tracking down and imprisoning deserters.
An important third level Nightmaren, called Goodles, fly around the worlds and carry keys that open cages and gates, ultimately leading to Second Level Nightmaren boss fights and, in one case, to Wizeman himself, making them more important then the common Nightmaren. Another example of their importance is Reala's constant reliance on them to guard the keys to NiGHTS' cage; a very important task considering how badly Wizeman wishes to have NiGHTS returned. Despite their important tasks Goodles have no defense aside from speed and are powerless to stop NiGHTS if they are caught.