Nu are enigmatic, blue creatures seen in nearly ever era of the game. Their purpose and origin are unknown. The Enlightened Ones kept them as assistants in Zeal; Belthasar had a personal, robot-like one that came with him to or was built in 2300 A.D. This Nu helps Crono become familiar with the Epoch. There are six Nu in 12000 B.C., all of them inhabiting Zeal. The Nu Guardian at the Lost Sanctum suggests that Nu can live for millions of years. A special book located there yields the following written verse on these creatures:
All life begins with Nu and ends with Nu...This is my belief...at least for now!
Despite their low HP, they do have a very powerful attack that will instantly reduce a characters to 1 HP, no matter what the character's level. Spekkio appears as a red Nu once the player reaches Level 99. The Nu are often seen by fans of the series to represent the power of the planet at work, or perhaps its life force. According to Chrono Cross, as well as evolutionary theory, life rose originally in Earth's oceans, and the Greek letter nu is often taken in old writing to represent water. It is also the symbol for wave velocity in the mathematical formula for frequency.
Home Area: Viper Manor
Belthasar's Nu assistant seems to have carried over, as a BeachBum (thought to represent a Nu) resides in the library of Viper Manor where the Neo Epoch is kept. He can change the names of members of Serge's party. It is apparent that a Nu was at one time planned to be a playable character; its dialogue icon appears in the Chrono Cross Demo disc's data and its design is distinctly Nu (not BeachBum).
Theory and Analysis
An article exists solely on the meaning of Nu, called The Secret of Nu.