Rust Giant
From Transformers Wiki
The Rust Giants are mechanical beings of unknown origin. Aggressive and warmongering by nature, they are covered in rust and have mostly similar shapes but can vary in size.
Fiction
2005 IDW continuity
While in the vicinity of Miliarium, the crew of the Lost Light stopped to liberate a city under attack by Rust Giants, Tailgate punching out their biggest, baddest guy. How Bright Their Frail Deeds
In a marketplace on Troja Major, Anode stole a set of mood pipes from a Rust Giant merchant, who demonstrated his displeasure by chasing Anode, Lug, Velocity, and Nautica through the crowded market. An Axe to Break the Ice