Mini-Con

Mini-Cons are a race of small Transformers capable of powerlinking with a larger Transformer and to impart extra abilities or greatly increase their strength.

Japanese term: Micron
French-Canadian/Spanish term: Minimodus

3H Wreckers Comic

Ramulus mentions the existence of Mini-Cons.

Unicron Trilogy

Animated Continuity

Unicron created the Mini-Cons to be mindless tools, sent to Cybertron as an agitating element to the Transformers' civil war. The power-enhancing "smart tools" would be unleashed upon the populace, who would snap them up, bond with them, and the war would only get bloodier, as Unicron drank in the negative psychic energies from the death and destruction. Once he'd gathered the power he needed, the Mini-Cons would turn on their supposed masters, incapacitating them, and Unicron would fully awaken to devour the planet and all Transformers on it, eliminating his biggest obstacle to devouring all of existance.

But through a strange warp in space and time, three human children from the future -Rad, Carlos and Alexis- were sent to the Mini-Cons' birthing chamber on Cybertron just seconds before the small robots emerged from their pods. As the Mini-Cons had been designed to form mental bonds with other life forms, when Rad touched the Mini-Con who he knew from the future as High Wire, High Wire apparently formed his bond then, with Rad... and through the Mini-Cons' shared "soul dimension", the Linkage, sentience and free will spread throughout the Mini-Cons, forming "souls", and crippling Unicron's plans drastically.

Dreamwave Comic Continuity

Mini-Cons are a 3rd race of Transformer, mostly living in designated sectors to to themselves, which left the open to attack when Megatron led his Decepticons on capture raids. Mini-Cons are capable of adding their power (disproportionate to their size) to a Transformer with whom they powerlink. Mini-Cons are also capable of tapping an extradimensional energy source of unknown origin, but are wary of doing this, and most have inhibitors installed to prevent this from happening.

Over-Run, a Mini-Con refugee from another dimension led Cybertron's collected Mini-Cons in tapping that dimension's energies and channeling them into an attack on Unicron which left him stranded on the far fringes of space. After Unicron's defeat, Most Mini-Cons re-established their villages in the Mini-Con sector. When Unicron appeared again 10 years later, no one went to fetch the Mini-cons to battle Unicron again, so it seems likely the Mini-Cons connection to their extradimensional power source was severed.

There is no indication that Mini-Cons are related to Unicron in Dreamwave continuity.

From Teletraan I: The Transformers Wiki, a Wikia wiki.