Viper was a Schwarzkopf sit-down looping roller coaster at Six Flags AstroWorld. It originally opened at Six Flags St. Louis under the name Jet Scream, but was relocated after the 1988 season. It was demolished along with Six Flags AstroWorld in the fall of 2005.
The ride featured a single loop, and two tunnels.
The ride was painted blue when it originally opened, but it was painted green when it was relocated.