Beast

The Beast is the combined form of the 5 Dinobots. Like them, his strength is awe inspiring, far beyond the other combiners. Unfortunately, he is also a mindless monster, whose single impulse is simply to kill, regardless of allegiance

=Fiction=

The Beast Within
With the autobots moments from death(some several moments passed death) Grimlock lays all his cards on the table and combines with his team mates into The Beast. After killing the decepticon combiners, and any decepticon foolish eough to attack him, he turned on the autobots, eventually forcing them to kill him

=Trivia=
 * The Beast has only ever appeared in the once of two part comic included wih the Metrodome Season 2 P2 and Season 3 dvds.....thank god
 * For years, fans have been coming up with designs for a dinobot combiner. This is such much worse then any of them