Energon cubes can be created by Soundwave, who generated the empty cube framework from his chest. So the Autobots were apparently unaware of them until their reawakening on Earth in 1984, when Hound described them to Prime as simply "some kind of cube". (This is a little perplexing in light of the fact that energon cubes were also shown to have existed by the time of Optimus Prime's creation at the end of Cybertron's Golden Age. War Dawn). It's a little confusing to why the Autobots never knew they existed?
The liquid energon within energon cubes is a glowing pink color, they can be compressed for easy storage and transport.
Now my little plastic bots/cons can fight over the most prized source of energy on Cybertron!
Me? I'm a Transformaniac through and through. I've been collecting for over 20 years and my collection is starting to outgrow "The Vault"! I collect, maintain and refurbish my Transformers and I am always looking for new (and old) ones to add to my 1000+ plus collection. Feel free to check out my collection, as it's ever-growing and I'll be updating my blog with new Transformers as soon as I get them.