The Development of Metroid Prime 4: Beyond — Interview

[Leynos]

CaptainExplosion said:

Leynos said:

Not really scary but the only moment in the Prime series that took me by surprise was when I played Prime 1 for the first time in 2002, went into a room I been through a dozen times and suddenly Chozo Ghosts. Driven insane by Phazon.

Isn't there an ending cutscene where we see the remains of the Prime Metroid, and from there a creepy hand with an eyeball pops out?

Not a human hand but humanoid hand. It's not exactly body horror or gory.  It's Dark Samus being born.