Fuzor Zoids are combinations of two or more individual Zoids or Blox units, resulting in the creation of a 'far superior machine'. The 'component' Zoids combine together, and are able to share power supplies, sensor units, and weapons. In some cases, the combination is able to unlock hidden weapons or capabilities in one of the component Zoids. However, for some Fuzors, not all of the cockpits of the two or more Zoids that are part of the Fuzor are used. Such Fuzors include both Gairyuki Fuzors.
Fuzor Zoids were one of the key plot elements of the early episodes of the Zoids: Fuzors anime, as many of the characters raced to learn about the newly discovered 'Fuzor Technique', and to find out which Zoids are their 'Fuzor Partners'.
When two Zoids fuse, they become more powerful combined then they are individually. The example given in the anime is the Killer Spiner. Individually, the Dark Spiner produces 60,000 'zels' (units of power), while Killerdome produces 58,000 zels. However, when fused, the two Zoids produced a significantly larger total of 933,000 zels.
In Fuzors, only certain Zoids could become Fuzors. For example, while the Savage Hammer team had an abundance of Leoblazes available to them to form their Matrix Dragon, they needed a specific one to complete the Fuzor.
Most Fuzors had a limit to how long they could remain combined, as the fusion used significantly more power then a normal Zoid. For example, the Dark Assassins Team were defeated by Mach Storm when their Zoids were forced to separate. Others, like the Liger Zero Phoenix, could remain fused for effectively unlimited periods of time, although the Anime was largely inconsistent with these time limits.
The first 'Fuzor' released in model form was the 'New Japanese Release' Killer Spiner, a combination of the Dark Spiner and Killerdome Zoids. This was considered to be a unique gimmick until the release of the anime and TOMY's 'Blox' product line. As a result, its status as a Fuzor is a retcon.
The main selling point of the Blox line was that the components and weapons of the Blox Zoids could be attached to almost any regular Zoid, as well as combined together to form larger Zoids. The first 'official' Fuzors, the Matrix Dragon and Chimera Dragon, were each constructed entirely from the first four Blox Zoids of the Republic and Imperial factions respectively.
Many of the Blox Zoids were re-released in the U.S. and Pacific regions under the 'Z-Builders' product name. This range also included several Hasbro-designed Zoids, a handful of which were to be adapted and released back in Japan. Both the American and Japanese lines were cancelled before more than a small amount of adaptions could occur.
Some fans consider the Transfighters from the OJR Line to be Fuzors as well.
The Blox Changing Armour System (referred to as Blox-CAS or B-CAS) is a subset of the Fuzor Technique, used with the Liger Zero and Gairyuki. Normal CAS Units are little more than a set of armor, weapons, and equipment 'swapped' onto the Zoid's basic frame. However, Blox-CAS Units are designed to function as independent Blox Zoids when not in use as a CAS Unit.
The Fire Phoenix and Jet Falcon are the primary examples of Blox-CAS units; both are capable of fusing with the Liger Zero in place of its standard armour. The Gairyuki's armor is also made of two (later three) unmanned Blox Zoids; Hien, Gekkou, and Raiden.
The Zoids in this table are Fuzors as depicted by the models' instruction manuals, in the Zoids: Fuzors anime, or in promotional videos released with the models, such as Rayse Tiger's DVD. Other Fuzors are depicted in the box artwork of the various Blox and Fuzors line model kits, but there are no details beyond these photographs. There are also Fuzor Zoids in the Video Games series using the unison command in the battle screen in Zoids Saga DS. For example, Victory Liger and Victory Rex makes it Victory Liger VF.