A Decepticon whose alt-mode is a combat-capable jet or other atmospheric craft, by standard carrying both a beam weapon and a long-range missile or bomb launcher. The supremacy of the Seeker model over Autobot combat aircraft is such that the Seekers have dominated the skies of Cybertron for kilovorns.

A triple-changer cannot be a Seeker. Neither can one whose alt-mode does not possesses offensive weaponry, nor one whose alt-mode is primarily space-capable, freight bearing or troop-transporting. The group of build-lines produced the factories of Vos. The five main lines of this group comprise the majority of the Decepticon air military.

The five great lines are:

• Seeker - the most common line, standardized since the late Golden Age. Seekers are on par in size with the Standard Large frame of Tarn but weigh only a tenth as much. Seekers convert into fighter jets and are so common amongst the Decepticon ranks that they are often called hunter-seekers or Vosians as if they were the only model Vos produced.
• Hunter - fifteen percent taller than the Seeker model and equipped with heavier armour, more munitions and more fuel. Designed to fulfill the role of a main battle tank in aerial combat. Hunters are not bombers; they are designed to be deployed in air-to-air combat alongside other Vosian models, supporting them with their longer-range firepower, greater endurance and larger fuel capacity. Also flying tank, long-ranger.
• Flayer - twenty five percent taller than the Seeker model, Flayers are Vosian bombers. Flayers have little direct air-to-air offensive capability but can carry large numbers of Chasers to act as a protective swarm. A wing of Flayers can carry enough munitions to level a town. Flayers are the most problematic of the Vosian lines, with a tendency towards depression and mental illness that has made the line unpopular. The few Flayers seen in recent millennia are all survivors of old production batches.
• Chaser - slightly more than half the size of the Seeker model, Chasers are designed to be air-to-ground gunners and strafing attackers. Chasers  were developed from the kerazeer [see Jalansalan], originally designed in order to increase the number of operational Decepticon troops quickly and cheaply, doubling the number of troops that could be put into the field at the cost of versatility. Chasers are only produced when the Decepticon army is suffering from high losses due to being outnumbered and outgunned by a ground-bound enemy. Also [derogatory]: kernazeer, zaarn, sawnoff, stuntie, runtling, jetling, minijet, shortie, kneebiter, toyplane, flying fury, windling, wingling; anything that is small, flight-capable and highly hazardous to one's health, especially when one makes jokes about its height.
• Seizer - the air-to-ground variant of the Seeker. Seizers are much the same size and weight as Seekers but have their wings aligned along their legs and their nosecones mounted on their heads. The Seizers are designed to fly very close to the ground, and are often equipped with vertical lift engines, so that they can deploy their undercarriage claws against ground vehicles. The Seizer model is quite common but most Autobot are unaware of its existence, believing Seizers to be the same as Seekers. Ramjet, Thrust and Dirge are all Seizers.

"Hunter-seekers" is the correct collective term for the five build-lines, but Seekers are so generic that often Hunter-seekers are simply called Seekers. The five build-lines are also collectively known as Quercons. "Seeker" has become an by-word in Core Group for a vain, self-important wimp. Autobots use "Seeker" to refer to any Decepticon with a jet form, whether combat-capable, triple-changing, cargo-bearing or other.

Other everyday phrases involving Seekers include:

• Easy as taking wings off a Seeker - very hard, verging on impossible. 
• Quiet like Seekers - very loud.
• Retreat like Seekers - to withdraw at supersonic velocities; to run extremely fast. 
• Seekers did it - what one tells one's commander to explain why and how something that should not have happened has happened.
• Vain as a Seeker - one who spends a lot of time working on his exterior finish.