Nomads are level 3 neutral creatures recruited from the Nomad Tent.
"Native to the desert sands, nomads are fast riders able to traverse sand with the ease most travel over grass." AB manual
Nomads' sandwalker special ability causes hero to ignore terrain penalty on sand. This ability applies if the hero has at least one nomad in his army.
Sand is not nomads' Native terrain, so they will not receive any benefits from fighting on sand. As with other neutral creatures, nomads have no native terrain.
Nomads were added in Armageddon's Blade, so there are no Nomads or Nomad Tents in Restoration of Erathia.
[Show user commentary]
[Hide user commentary]
Nomads are invaluable on maps with lots of sand. Giving one to each of your scout heroes will eliminate the need for Pathfinding. In large numbers they can also be good attackers, although building enough of them can be difficult.