Titanium Series was a multi-brand toyline manufactured by Galoob under the Micro Machines banner. Transformers was one of the Hasbro properties licensed into the line. The Transformers portion of Titanium Series began in 2006, both at the 6 inch and 3 inch scales.
Titanium series featured primarily die-cast metal models and statuettes of ships and characters from the Hasbro properties included in it, and its inclusion of Transformers was no different. The Transformers Titanium toys were available in two size classes: the 3 Inch Robot Masters (not to be confused with the Japanese toyline Robot Masters), and the 6 Inch Cybertron Heroes (not to be confused with the Heroes of Cybertron PVC minifigures). The Robot Masters were non-transforming replicas of robots from many series (and one spaceship, the Ark), made primarily of die-cast with some plastic parts. Each came with a transparent plastic base tampographed with either the Autobot or Decepticon symbol. Each figure included only a couple point of articulation, usually at the shoulders, neck, and waist. They were generally sculpted in some sort of action pose, often making the articulation moot. Some included removable weapons, which were tailored to the figure's hands and could not be interchanged. As well as collecting figures from many unrelated Transformers franchises, the line had an upshot of including characters and incarnations not previously released in toy form, such as robots from the contemporary War Within comic book series.
The 6 Inch Cybertron Heroes went a step beyond the 6 inch figures from other Hasbro brands, in that they were transforming figures rather than statues. They included a mix of die-cast and plastic, maximizing the use of metal early on, while later figures were almost entirely plastic. Like the Robot Masters, the Heroes included characters from a number of series, but featured comic-only characters even more heavily. Unfortunately, the construction of the early figures was prone to issues with looseness and breakage, as well as paint chipping from metal-on-metal contact during transformation. Each figure also included a plastic display base, with a removable badge sculpted with the character's faction symbol and stickered with its name. Many toys also included non-interchangeable accessories.
Titanium Series Transformers suffered from similar distribution problems as Alternators: since each wave had very low variety, retailers would not purchase the next assortment until the current stock had sold, but the market was already saturated for the figures on the shelf. This led to spotty release of the final waves, and eventually cancellation due to flagging sales. The cancellation left a wake of unreleased figures at varying stages of development. Some of the planned toys were eventually released as store and event exclusives. A handful of Movie era figures were released through Toys 'R' Us co-branded with Revenge of the Fallen, and a few more redecos were sold at Target co-branded with Universe (2.0), though without the plastid display bases, to keep the price point down. The line proper ended in 2007, with exclusives and co-branded items straggling until 2009