The Nomad is an enemy in Chrono Trigger that appears in the Black Omen. They appear with Watcher. They will escape after a certain amount of time from when the fight begins, the best strategy is to kill the Watcher first, preferably in one hit and concentrate on killing the Nomads. Killing them gives you a massive exp and TP bonus. They're notoriously hard to hit, and since your Techs and items have been locked by the Watcher, they're pretty difficult to kill off before they run away. Alternatively to save an extra turn equipping fire resistant armor should be enough to ignore the damage from the Watcher and attacking the Nomads before they leave the fight, since they will leave the fight regardless.