Species (1995)

In 1993, a search for extraterrestrial life, a transmission's received, detailing an alien DNA structure, along with instructions on how to splice it with human DNA. The result is Sil, a sensual but deadly creature who can change from a beautiful woman to an armor-plated killing machine in the blink of an eye. Government agent Xavier Fitch assembles a team of scientists and mercenaries to locate and destroy Sil before she manages to find a mate and breed.