The Volt Monster myth originated from unknown sources on the web regarding a mutated monster living behind the alley of Pay 'n' Spray in Washington Beach.
The myth is mainly a result of the obscure warning signs in the alley. The signs include warnings about petroleum mixture and high voltages. As a result, myth hunters claim that the alley is inhabited by a monster formed as a result of petroleum mixture and electricity, making it a predecessor of the Toxic Creature from Grand Theft Auto IV.
However, upon analysis of technical files, no such monster is ever found. It may be referenced elsewhere than the warning signs.