Scorponok [Goes w/ Blackout (Grindor)]

Scorponok is a small Transformer with a symbiotic connection to Blackout. Just as Blackout would often be found looming powerful and silent by Megatron, Scorponok is always near Blackout, except in those times he has been sent to kill.
His main drives are to hunt, destroy, and hunt some more, causing many to view him as barely sentient. Others are concerned that he actually be a cunning opponent getting friend and foe alike to underestimate him... and the later are right. In secret, Scorponok has proven to be astonishingly erudite and focused on patient, long-game operations.
Since he can tunnel underground with frightening speed, he's incredibly good at ambushing. His favorite pastime is playing Hide and Seek with unsuspecting players, be they robotic or organic. He prefers to be hider and seeker. On Cybertron, he was deliberately left behind on battlefields so he could use his chameleon mesh armour plating to blend in perfectly with the background, then ambush any Autobot patrols that would arrive. Thanks to this, Megatron gave him more autonomy than other Decepticons would get, as he admired Scorponok's genocidal zeal.
He may retreat, but he'll come back. He kills Autobots. He never gives up.