The franchise consists of four main installments, each following the terrifying evolution of human-alien hybrids:
: Explores the infection of an astronaut returning from Mars, introducing a malevolent male hybrid.
While "Species 5" is often searched for, it typically refers to unofficial fan-made compilations or recent science fiction movies like Endangered Species (2021) that are marketed similarly in Hindi-speaking regions.
: The original film introduces Sil, a beautiful but deadly creature created by splicing human DNA with a message from space.