In Aliens, the android played by Lance Henriksen is Bishop.
Bishop is the synthetic human assigned to the Sulaco, the military spacecraft carrying the Colonial Marines to LV-426. Unlike Ash in Alien, Bishop is openly identified as an android early in the story, although several characters remain suspicious of him because of the earlier film’s betrayal.
Bishop serves as the expedition’s executive officer and uses advanced abilities, including rapid data processing and remarkable physical coordination. His most famous scene involves demonstrating his skill with a knife between Hudson’s fingers, while his later actions help the survivors escape the alien-infested colony.
Bishop is sometimes confused with Ash, but Ash belongs to the Nostromo crew in Alien. Lance Henriksen returned as Bishop in Alien 3, where the character’s fate and Weyland-Yutani’s android designs become important to the wider series.