Of all of Deathzaras's warriors, Hellbat is by far the most underhanded and maniacal. As a member of the elite Breastforce team, he thinks that he would be much better suited to lead the unit than his commanding officer, Leozack, and he goes to any lengths that he can to prove it to Deathzaras. Hellbat is a highly accomplished spy, regularly obtaining information that none of his fellow Decepticons are able to, and formulating any number of plans and schemes in his never-ending quest to climb the greasy ladder. He is also a sneak of the highest order, constantly talking behind his teammates' backs and spreading rumors, but he's not sneaky enough to prevent his fellow Decepticons from knowing what he gets up to. It is perhaps not surprising, then, to learn that nobody likes Hellbat, and that they trust him even less than that. In fact, his teammates would all be quite happy to kick him out of the Breastforce, if not for his strangely skilled silver tongue. Hellbat is usually able to talk just about anyone around to his way of thinking just long enough. He would genuinely go to any length to keep his position in the Breastforce ranks, although he'll usually come off as just plain pathetic in the process.
In robot mode, Hellbat has one of the most useful special attacks among all the other Decepticons: with a chant of "Saimin, suimin, tōmin, Hellbat!" ("Hypnotism, sleep, hibernation, Hellbat!"), he can project mesmerizing waves of sonic energy that weaken his opponents, leaving them open to his influence-or his teammates' attacks. His breastplate, Kōmoribreast, can detach and transform into either a bat-like robot mode (equipped with an energy-draining whip in its mouth), or the hand-held "Kōmori Cannon" blaster. Like his fellow Breastforce warriors, Hellbat is also armed with an Electromagnetic Nunchaku. So it's a pity, then, that he's kind of a schmuck.
(Source: Transformers Wiki)
