Doomsayer

Doomsayer may refer to:
 * A doomer or peaknik (believer in drastic consequences from the peak oil theory)
 * A character class in Deadlands: Hell on Earth
 * A person or doomsday cult claiming a doomsday prediction
 * A prophet, oracle, or seer who reveals the fate of someone or something
 * Any person who makes pessimistic predictions