- "All life begins with Nu and ends with Nu. This is the truth! This is my belief!...At least for now."
- — "The Mystery of Life," vol. 841, chapter 26
Nu are creatures found throughout Chrono Trigger.
Nu can be found in the Cursed Woods of Middle Ages, the Hunting Grounds of Prehistory, and at Enhasa in Antiquity. At the Cursed Woods and Hunting Grounds they only appear when it rains. Nu work as merchants or assistants during 12,000 B.C. Nu can also be found scattered throughout the game. Other Nu include: Nu Guardian, Nu Master, and Pink Nu.
Nu found in Prehistory can be a good source of Tech Points early on in the game. Nu there are also a good way to get ingredients needed to purchase equipment in Prehistory. However, the Nu only appears when it rains. You must find Nu before the rain stops. If you do not, then Nu will leave until the next rain. The first time you defeat the Prehistory Nu, he rewards the party with a Third Eye.
In the secret room of Enhasa, there are six Nu. Each will attack random party members with one of the two Head-Butt attacks.
There are Nu working as merchants in Antiquity, Arena of the Ages, and Black Omen. There is a Nu in the Laruba Village that can change any character's name. A Nu can be found inside the North Palace. The two Nu that appear in the Black Omen do different things to assist you. The one on the left hand side of the DS screen lets the character buy and sell things, while the Nu on the right offers to let the player escape the Black Omen.
At least one Nu was built by Belthasar. In the Future, this robotic Nu helps the Guru build Epoch. Upon his death, he programs the Nu with his memories and the Nu gives the player the time-traveling ship, advises Marle to find a Doppel Doll to help revive Crono, and sends three special Poyozo Dolls to Death Peak to help them scale it. A second Nu specifically mentions him. It is unclear whether or not all Nu were built by him. If they were, their presence in eras outside of Antiquity could be explained by the same rifts that transported Schala, Janus, and the three Gurus. This may also explain how the Nu on Mount Emerald was seemingly able to survive millions of years.
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).
Alongside a Poyozo named Mamo, a Nu tries to recruit members for their group "Nuumamonjaa". Finding no one willing to join them, they wander the fair and interrupt the robot Johnny's show. Attempting to win a golden shovel at the Fast-Drinking Contest in Leene Square, Mamo volunteer's the Nu; it is quite clear that the Poyozo pushes the Nu around. During the game, the Nu tips the table and drinks every glass in one gulp, quickly becoming full. The Poyozo proceeds to plug a SNES controller into the Nu to take control and win the game. This scene seems to support the notion that all Nu are robotic.