Dreadbot was incarcerated after he killed nine people. He was later released, after negotiations done by Megatron, in order to help him hunt down Cade Yeager. Dreadbot followed Megatron to Yeager's scrap yard, and eventually to a nearby town, but the Autobots Bumblebee, Drift, and Crosshairs stood in their way. During the fight, both Megatron and Dreadbot were damaged in a trap set by Yeager and Grimlock snared Dreadbot in his mighty jaws, killing him.
Dreadbot's Alt mode
If you can look closely to Dreadbot's right arm, you can see Christmas lights.
Dreadbot's CGI model is a reuse of Crowbar's with slight modifications done to match his vehicle mode.
Prior to the film's release, Dreadbot was originally known as Hooligan. Ironically, this was an early name for Crowbar as well.