The Timulator was a time machine used by Bowser during the events of Mario's Time Machine. The time machine has three settings: the City, the Date, and the Epoch (BC or AD). Once a destination is set the user then is required to surf through the fabric of time, collecting Mushrooms. Once enough Mushrooms are collected the user then enters a portal and is sucked into the destination programmed in the Timulator. If the user enters a portal too soon or has set a destination not within the game's story (e.g. Menlo Park in 2001 AD), the user is dumped back in 1993 (the present). The Timulator also comes with a remote control device, which at the press of a button returns its user to 1993 from any area in time.
Bowser initially used the Timulator to travel to significant points of human history on Earth, and snatch various artifacts to display in his museum within his castle, including the Declaration of Independence and Joan of Arc's shield. Mario gained control of the Timulator to return the items to their proper places in the timeline before the timeline would've changed forever. After Mario succeeded in restoring history back to normal and tracked down Bowser, Bowser attempted to use the Timulator and escape to an area of time known as "Paradise", but the machine overloaded, self-destructed and catapulted Bowser into the Cretacious era, where he was quickly stomped on by a Tyrannosaurus Rex.
In some versions, Bowser also had a far more sinister intention with the timulator: Specifically, after stealing all artifacts for his museum, he will have the timulator self-destruct, ensuring the Earth falls into a new Dark Age.