Watch Scooby-Doo 2: Monsters Unleashed (2004) HD Full Movie Free on SolarMovie. Watch Scooby-Doo 2: Monsters Unleashed (2004) online free. The Mystery Inc. gang must save Coolsville from an attack of their past monsters brought to life by ...The Mystery Inc. gang must save Coolsville from an attack of their past monsters brought to life by an evil masked figure trying to take down the gang.