Formerly a slave in the hidden Decepticon pits of Cybertron, Hotspark managed to escape with Bulldozer and spent a brief time with the Autobots. Quickly realising it wasn't for them, they left and embarked on a career as hired guns. He is friendly and generally well tempered, but can be lethal when crossed. While he enjoys combat, he doesn't activly seek it out, which makes others within Guardian Corps wonder why he bothered signing on with them. Hotspark could almost be a beserker when in battle, and many find themselves dodging his blasts just as much as the enemies.

In robot mode, Hotspark is armed with a magma whip that can scorch and sometimes melt parts of an opponent when used as it's maximum heat setting. He is also armed with a flamethrower gun that can reduce almost anything to slag. In dragon mode, Hotspark can shoot fire from his mouth, and it is just as lethal as that from his gun. Hotspark is impervious to any type of high temperature attack, as such, most conventional energy weapons have little effect on him.