Overflow is half of the Autobot Battlefield Headquarters team, along with his combiner partner Full-Barrel. He is calm, meticulous, and would spend hours perfecting his battlefield strategies, if he didn't have to keep an eye on Full-Barrel all the time. 
- Micromaster Combiner Autobot Battlefield Headquarters (1990)
- Accessories: "Battle truck", 2 "scrambler guns", 2 "laser machine guns", 2 "air-to-air missiles", 2 "cruise missiles"
- Overflow transforms into the rear half of a tractor-trailer rig. He was sold with Full-Barrel, and together they came with the massive Battlefield Headquarters.
- Amusingly, Full-Barrel and Overflow form a perfect miniature version of the Battlefield Headquarters they drive, even having the Headquarters' folded wings sculpted into their sides. Both the Battlefield Headquarters and Full-Barrel/Overflow even split in the same place in vehicle mode.