Renegade Decepticon

The renegade Decepticons are (predictably) Decepticons from the cartoon portion of the Generation 1 continuity family.

There were going to be six Combaticons, but then Starscream got hungry.

The renegade Decepticons are Decepticon political prisoners held on Cybertron. Under Megatron's orders, Shockwave had destroyed their bodies but saved their personality components, storing them in the Decepticon Detention Center.

Fiction

The Transformers cartoon

It is unclear when the renegade Decepticons were imprisoned, but it quite likely was four million years or more ago. Liberation eventually came at the hands of Starscream, who had been banished from Megatron's Earth-based forces and wanted to build an army for revenge. He infiltrated the Decepticon Detention Center and sought out Cell 217, which contained a wall of countless drawers. Inside one of them were the renegade Decepticon personality components he was looking for; taking them, he shot several explosive blasts at the remaining drawers and then headed back to Earth. There, Starscream gave the renegades new bodies and called them the "Combaticons." They didn't recognize him, and his imperious attitude irked them, but their common goal of revenge against Megatron (along with some blackmailing) fostered a tense alliance. Starscream's Brigade

Notes

• It is uncertain whether the Combaticons constitute all of the renegade Decepticons, or if more were left behind in the Detention Center. (Though even if there were more, they likely were destroyed when Starscream demolished Cell 217.)
• The script called for the personality components to be contained in a glowing green box with a label identifying them as criminals. That, in turn, was to be contained in a "metal drawer" within a room "not unlike a bank vault". Oddly, while the art missed the mark on the glowing box (making it look like an ordinary energon cube instead), the "bank vault" direction was taken literally, right down to the keyholes on the drawers.