SA-X (Metroid Fusion)
The Metroid series has always had the potential to play out like a horror game, and Metroid Fusion takes advantage of these elements to craft another thrilling experience. The game starts out with Samus Aran on another mission, this time acting as a bodyguard for a research team as they visit the planet SR388. She encounters an alien and manages to kill it, but they soon find out that it was infected by some new kind of parasitic organism called the X.
This parasite nearly kills Samus after infecting her, but the medical crew manages to save her life. Strangely enough, most of her Power Suit had been integrated into her body, forcing the medical team to surgically remove large portions of the infected suit. Little did they know that the X parasite managed to use the infected portions of the Power Suit to create a splitting copy of Samus, albeit much more chilling and ruthless.
Dubbed the SA-X, this creature will hunt down Samus throughout her mission with the prime purpose of killing her. The worst part about most of these moments is that you cannot kill the SA-X and must avoid it at all times. In a way, the SA-X acts like some sort of stalker from horror films who always finds a way to find their prey.