Ironhide is the Autobot's Weapons Specialist in Transformers: Dark of the Moon.
Ironhide makes his first appearence in the film at the NEST Base - where he is given a large cannon by Wheeljack. He than says to Director Mearing that Optimus is angry - and that he should make something of himself (Transform).
Ironhide makes his most notable appearence in the film when he is leading Sentinel to their base in Washington D.C. He and Sideswipe encounter two of the three Dreads - Crankcase and Crowbar. Ironhide slams into the two and the tro transform in mid-air. Attempting to have them surrender, Ironhide, Crankcase, Crowbar and Sideswipe drop their weapons - to which Crankcase reveals two spiked boom-sticks, and throws one at Ironhide's chest. Ironhide and Sideswipe battle the two before Ironhide shoots Crowbar in the head with his Heavy Iron Cannon. Ironhide than uses the spiked boom-stick against Crankcase by stabbing him in the face with it, than tossing him down on a car and kicking him into an Auto-Repair Shop - which exploded.
Back at the base, Lennox orders Ironhide to hide Sentinel - and Ironhide says to consider it being done. However - Sentinel reveals that he had made a deal with Megatron - and shoots Ironhide twice in the back with his Cosmic Rust Blaster, to which Ironhide's body begins to rust. Sentinel shoots Ironhide a third time, causing him to begin to fall apart, until Ironhide's body is entirely rusted and shattered, and his head decapitated by the rusting effects.