Sebastian De Rosa, played by Raul Bova, is a character in the 2004 film Alien vs. Predator.
An Italian member of the team of explorers hired by Charles Bishop Weyland to explore the pyramid, De Rosa serves as the team's archaeologist and linguist, translating the writings on the walls of the pyramid to learn the story of the Predators and their hunts.
When the pyramid shifts, he gets trapped with Weyland, Stafford and Lex. After a Predator attack, he and Alexa are the only ones remaining. After being chased by Scar, the pyramid shifts, just in time for them to escape into another room. There, they watch Scar kill a facehugger and an Alien, then witness him mark himself with its blood. After Sebastian translates the hieroglyphs around them to learn that the Predators have come to Earth as part of a ritual to prove themselves, Alexa and Sebastian conclude that they must return Scar's gun to him.
When the pyramid shifts once more, they are chased by Aliens to a cliff, where Alexa just misses the other side and Sebastian is forced to lift her up. Just then, the Alien "Grid" appears right next to him, and drags him off to the hive. Later, she and Scar find De Rosa cocooned in the hive. He pleads for her to kill him, having stated that "it" is already inside of him. She honors his wish, and shoots him in the head. Moments later, his chestburster emerges, but Scar immediately kills it.