Energon cube
This is the safest form of energon, used for transportation and storage.
Fiction
G1 Animated Series
As originally introduced, energon cubes seemed as though they could only be created by Soundwave, who generated the empty cube framework from his similarly-shaped chest, but later, several other Decepticons proved able to produce them as well. Energon cubes are a Decepticon invention - precisely when they were concieved is unclear, but the Autobots were apparently unaware of them until their reawakening on Earth in 1984, when Hound discovered their existence, but could refer to them only as "some kind of cube." By 2005, however, the Autobots had begun to use energon cubes for power as well.
Exactly how an energon cube operates is unclear - mostly frequently, the empty cube is simply attached to or placed near the energy source from which it is to drain power, and the energy in question is automatically converted into liquid energon that fills the cube. Energon cubes have proven able to transform vast amounts of resources into energon, including electricity, magma, oil and steam. Like the other forms of energon, the liquid energon within energon cubes is a glowing pink color, although the cubes could also be compressed for easy storage and transport, causing them to take on an irridescent rainbow effect.
In Beast Wars, it seems that energon cubes also occurred naturally, as a 'stable' form of natural energon. However these were a fraction of the size of the G1 Energon Cubes and seemed to be solid Energon rather than a cube containing it. They were also blue, rather than pink.
Toy
Energon Cubes were available with Takara's "TF Collection" reissue of the Insecticons, and the set's redeco, the Collector's Edition Insectron Clone Army (Shothole, Salvo and Zaptrap) box set released in Japan in 2004.
