Observer (StarCraft)

Observers are the protoss' mobile detectors. Although observers are 'permanently' cloaked, protoss players must be more alert to enemy anti-cloak units; the observer's low health gives little time to escape attackers. Observers are cheap enough to have a handful accompany an attack force, especially against a target with many detectors.

Quotations

 * See: StarCraft Observer Quotations

Development
The observer was initially called the "witness."