Transmetal

A Transmetal is a (generally) Vok related enhanced form of a Beast Wars era Transformer, featuring a "mutated superstructure".

Normal Transmetal

In beast mode, the Transmetals seemed almost, if not entirely, mechancial, much like the animal Transformers of the previous Generation 1 franchise. However, as part of a partial "inversion", many of their robot modes now bore organic elements, such as Cheetor's furry chest. Transmetals also typically featured a third "mobility" mode. While not full vehicular modes, these half-modes gave aspects of a vehicle to the existing beast forms. Examples include Rattrap as a wheeled rat and Megatron as a jet-powered inline skating enthusiast.

Beast Wars animated series

The Transmetals are created as a result of transformers being bathed in a quantum surge after the destruction of the Vok Planet Buster. All the Beast warriors who were not "born" from a protoform on Earh or sheilded in a CR Chamber were transformed. (Why those born from an Earth fallen protoform should be immune to the wave's effects is unknown.)

The affected characters were Megatron, Tarantulas, Rattrap, and Cheetor. Scorponok and Terrorsaur were in the middle of their mutation when they fell into lava pits beneath the Darkside and perished. Optimus Primal, Rampage, and Depth Charge also eventually became Transmetals as a result of the surge.

Most Transmetals have additional weapons and seemingly enhanced power levels. They are are immune to many Vok weapons, and may even be immune to the effects of energon radiation. (This last point had little bearing on the plot, since most of the energon deposits on Earth's surface had been destroyed by the Planet Buster cannon.) According to Ben Yee, the Transmetals were originally conceived of by Beast Wars writers as "absorbing" energon radiation and then needing to later discharge that energy, typically as weapon energy. However, the only time this was hinted at in the series was during "Bad Spark", when Cheetor "farts" a little energon cloud.

Interestingly, the Fuzors Silverbolt and Quickstrike, like the Transmetals, were shown to be immune to Vok technology, implying perhaps that all post-quantum surge Beast Warriors possessed some Transmetal qualities.

Toys

In addition to the characters mentioned above, Transmetal toys were also produced for Rhinox, Airazor, Waspinator, Terrorsaur, and technically Inferno (the Scavenger toy was initially intended to be his TM form, and was so in Japan and the UK.) None of these appeared on the show.

Scorponok, Blackarachnia, and Dinobot, though also not Transmetal in the show, were given their own Transmetal toys as Happy Meal pack-ins from McDonalds. Claw Jaw and Spittor were repainted and sold as Transmetals in European markets with a video.

Transmetal 2

Near the end of the series, a new breed, known as Transmetal 2s appeared. These new forms blurred the line between the mechanical and the organic even further, with equal parts of both appearing in both modes in an asymmetrical patchwork like jumble. This often resulted in somewhat monstrous looking designs.

Beast Wars animated series

Within the context of the television series the idea of a Transmetal 2 is somewhat vague. Only Cheetor, Dinobot II, and Blackarachnia are definitely meant to be Transmetals 2. Each of them was altered by an enigmatic piece of Vok technology known as the "Transmetal Driver" which appeared early in season three. The exact origin and nature of the Driver is unknown, although it was apparently found by Megatron at one of the Vok sites on Earth and likely altered to suit his own purposes.

Optimus Primal and Megatron also received new bodies in season three, in much the same fasion as each other, but only Megatron's toy was labelled a Transmetal 2. (Optimal Optimus was a normal Transmetal.) It is unclear whether, within the story of the cartoon, these bodies are meant to be similar to the bodies granted by the TM Driver. Both of their new bodies were the result of merging their sparks -- temporarilly -- with the sparks of their Generation 1-era counterparts, Optimus Prime and G1 Megatron.

Tigerhawk's toy is also labelled as Transmetal 2. His in-show origin involves both the fusing of two sparks -- those of Tigatron and Airazor -- and Vok technology. (The two sparks in question were both Beast Era sparks. It is unclear whether sparks from different eras are fundamentally different, and whether this would make any difference when creating Transmetal 2s.)

The new forms for all of these characters -- whether produced by the Transmetal Driver or by spark fusion -- were portrayed as substantially more powerful than normal Transmetals.

Toys

According to their toy packages and bios, the Transmetals 2 were all the results of Megatron's cloning experiments. This roughly aligns with the begining of the cartoon story, as the first Transmetal 2 that Megatron attempted to create was his resurrected Dinobot clone. This cloning experiment angle also helps to explain the presence of Optimus Minor.

Unlike Transmetals, most Transmetals 2 did not have a third mode. Only the largest TM2 toys -- Tigerhawk and Megatron -- were designed to have more than two modes, but Megatron's was never featured in the TV show and Tigerhawk's was dropped entirely even from the toy. Neither vehicle mode was especially well-implemented.

Early on in the release of TM2 toys, the packaging used a roman numeral "II", but a running change in the packaging was made to the arabic number "2".

IDW Beast Wars comic

In the IDW Beast Wars comics, a new group of Predacons travel back to the Beast Wars era (early in Season 3, around the episode "Changing of the Guard") and activate the remainder of the stasis pods ejected from the Axalon. The Transformers who emerge from these pods include normal beast-form Transformers, Transmetals, and Transmetals 2.

All the Beast Wars characters/toys not featured in the original cartoon (barring a few that traveled back with Magmatron) were given this same origin regardless of their "Transmetal" status. One possible explanation, though it is unsupported speculation, is that varied levels of shielding or protection in the stasis pods allowed different protoforms to mutate to different degrees when exposed to the quantum surge. However, it should be noted that among the cast of the TV series, it was the Transformers who had come from stasis pods on Earth prior to the wave that appeared to be totally immune to the effects of the surge.