NiGHTS into Dreams .Com

JP Remake Translation:

"A very cheerfully, innocent, race inhabiting Nightopia, the world of dreams. They love having a good time, which they do by showing passing visitors fun dreams doing things like singing or dancing. It's just in their nature to do whatever they can to let visitors enjoy themselves!"

In NiD Nightopians can be found within all of the levels bar Twin Seeds. They are a part of the games "A-Life system", and depending on how you treat them the music will change. This can be monitored on the "Christmas NiGHTS" demo disc, allowing you to see the happiness level of each Nightopian. This was included in the PS2 remake as well, and later on in the more recent port for PS3, Xbox 360 & PC.

The Nightopians have no hierarchy and are incapable of working together for a common goal. Through specific breeding however, a Superpian can be created (Malan has created a guide here for us all to use) which even builds a castle within the level it was created. 

In JoD the Nightopians act the same as they do within levels in NiD, but in this game there is another feature. If you Paraloop either Nightopians or Nightmaren, instead of killing them like in NiD, they are transported to a separate world called "My Dream". Here they can be kept and are fed with Blue Chips. Any Nightmaren paralooped to here will eat Nightopians though, so it is in your best interest to remove them. Depending on how many Mepians or Nightmaren you have, the landscape will change accordingly.

Mepians are present in both games and are created the same way within the games; by throwing a Nightmaren, turning it into a sphere, and allowing the sphere to come in contact with a Nightopian. This will create an egg, inside of which is a fusion of the two called a Mepian. It is essentially a Nightopian with randomised Nightmaren features.