Grand Slam is an aged and weary veteran of far, far too many battles. He has stood witness to conflict on hundreds of worlds across the galaxy and has dedicated his existence to creating an audio record of the Autobot-Decepticon conflict with all its pain, destruction, and disharmony that he hopes will one day, Primus willing, be played on a Cybertron that is at peace, serving as only a grim reminder of the horror that once consumed their world.
Marvel Comics continuity
Hundreds of years ago, a troop of Autobot astronomers on Cybertron detected the legendary Underbase making its way towards Earth. In order to alert their Autobot colleagues on that world, they encoded the information (along with several bonus features and "Making of the Underbase Legend" documentaries) onto two Mini-Cassette warriors, Raindance and Grand Slam. Their ship was damaged on the way, however, and the two Autobots crashed into the sea. The impact apparently left them insensate and mode-locked, for they never again demonstrated sentience or transforming capability.
The inert Autobots were found in their cassette modes by a band of 18th century pirates, who locked them away in a treasure chest just before storm destroyed their ship, sinking it in the ocean. In the present era, Decepticon leaders on Cybertron stumbled across this long-lost information, and commanded Ratbat and his Decepticons of Earth to find the lost tapes. They moved their disguised desert island starship to the rough coordinates of the shipwreck, and opened a Club Con vacation resort for fleshlings to disguise their true purposes there. The Seacons successfully retrieved Raindance and Grand Slam from the treasure chest, despite a brief altercation with the Autobot known as Blaster. Ratbat and his communications expert Soundwave were able to learn from the cassettes that the Underbase was set to pass by Earth in less than a week's time.
The cassettes were promptly forgotten about by all parties after this.
Dreamwave Comics continuity
Merged as Slamdance, Raindance and Grand Slam served as a correspondent overseeing the Pax Cybertronia between the Autobots, Decepticons, and Ultracons. Engineered by Ultra Magnus and accepted by Shockwave and Ratbat as a means for pooling their dwindling energy resources, the Pax was to be an ending of the Dark Ages. Unfortunately, a bombing run followed by an all-out assault by Starscream and his Predacons ended all hopes of an easy truce, and the dramatic return of Megatron with his cloned Aerospace Extermination Squadron ended any ideas of truce at all. Slamdance avoided the termination sweeps only by falling deep underground. He eventually linked up with the resistance movement organized by Blaster and Perceptor.
- Raindance and Grand Slam (Cassette 2-pack, 1988)
- Grand Slam transforms from a red and gold microcassette into a Cybertronic tank. He has two "dual repulsors" and a "smoke ejector" as chromed kibble which are added on to make his tank mode. He was sold with Raindance, and the pair combine to form Slamdance.