Zodiotron! was originally constructed by Dan Lankaster in Peoria Illinois in 1979 as a high school graduation present for his son Marty. Upon completion Zodiotron! was used to perform simple tasks like serving drinks, sorting mail and walking the Lankaster family dog Hooter. But as Zodiotron! was attempting to extract bubblegum from the hallway carpeting one afternoon he inexplicably became self aware and immediately began killing all humans he came into contact with.
In addition to the Lankaster family Zodiotron! murdered 80% of the Peoria population (see the Wikipedia article) before heading west to a small cabin in northern Colorado where he still resides to this day.
It is speculated that he abducted the Lankaster family dog Hooter and held him captive there until his death in 1989. Of course it is entirely possible that Hooter went along of his own accord as he never seemed too happy with the Lankasters anyhow.