This is the new addition to the Transformers Prime line up - Gaia Unicron.
After spending some time to assemble the micron, here is how it looks like. FYI, you will need to make some modification on the micron otherwise the claw is not able to move. Explore and you will know what I mean.
Below is to compare the size with the FE Optimus Prime.
What is so special with Gaia Unicron is that it can combined with Optimus Prime and also Megatron... and on top of that it also can be made as the head of the Supreme Class Unicron like what is shown below.
