The character of Optimus Prime first appears in the 2007 "Transformers" film as the leader of the Autobots in the search for the AllSpark. He intends to destroy it, even if it means sacrificing himself, before the Decepticons can use it to create a new army to conquer the universe. After arriving and scanning a Peterbilt truck, Optimus greets Sam Witwicky and Mikaela Banes, introducing his men and explaining why they have come to Earth. During the final battle, Optimus slays the hate-filled Decepticon Bonecrusher and faces his ancient enemy, Megatron. Unable to match Megatron in combat, Optimus urges Sam to push the AllSpark into his chest, which will destroy them both. Instead, Sam rams the AllSpark into Megatron's chest, destroying it and killing the Decepticon leader. The film ends with Optimus sending out a deep-space signal, inviting other Autobots to join them on Earth.