Heatmark

Heatmark is the form that Heatseeker and Slashmark make when they combine into one form.

Transformers: Robots in Disguise
In The Golden Knight, after successfully clearing a human town's roads of annoying squishies, Heakseeker and Slashmark combined into Heatmark to properly celebrate their victory. The arrival of Motormaster soon squelched their enthuiasm, however.

In Combine and Conquer, later while setting a trap for the Bee Team, the two combined once more, Heatmark eager to show what he could do to the annoying law-bots; Motormaster, however, was determined to use his own, bigger plans.

Trivia

 * In his first appearance, Heatmark's voice seemed to be a combination of Heatseeker's and Slashmark's, but later he clearly spoke using only Heatseeker's voice.