The Nomad is an enemy in Chrono Trigger that appears in the Black Omen. They appear with Watcher. They will escape if you kill the Watcher, but, as the Watcher has no Exp or TP bonus, it would render the battle useless if you let these escape. 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.