In both teaser and trailer, a Decepticon is shown multiple times as a Terex RH400 Excavator. It was revealed in February 2009 that the name was to be Demolishor.
Demolishor is cowardly when there's no leader, and he isn't the brightest one, but he's powerful enough to fight with multiple foes. He can use his excavator mode's tracks as wheels to travel and attack by moving one over his head to crush everything in front of him.
Demolishor protects a small Decepticon community in Shanghai after Megatron's death.
Demolishor shares his model with another Decepticon, Scavenger. This led to confusion for several months by fans if Demolishor and Scavenger were the same character or different. After information from novelization was revealed, it become clear that they were different characters. The movie clarifies that both Demolishor and Scavenger are of the same model of Constructicon.
Here is a picture of the bridge that Demolisher destroys
He is roughly 14 1/2 cm tall when standing up
This is an entry for the transformers rotf contest here