Alien: Earth mastermind Noah Hawley has divulged the rationale behind a significant twist in the beloved sci-fi horror saga.

The new eight-part drama, inspired by Ridley Scott's chilling 1979 masterpiece, acts as a prequel to the seminal space fright-fest that first unleashed the lethal Xenomorphs upon audiences worldwide.

When a precious research vessel plummets to Earth, a band of hybrids-synthetics endowed with human consciousness-set out on a perilous rescue mission, bringing them into direct conflict with the galaxy's deadliest creatures.

Yet, in a departure from previous chapters of the Alien narrative, the Xenomorphs aren't the sole menace threatening mankind's existence.

At the series debut in London, showrunner Hawley disclosed that viewers will encounter four new alien species previously unseen in the franchise, reports the Mirror.

While he's keeping the specifics of these new beings under wraps until the series premiere, Hawley shared: "I can tell you why I introduced them.

"Which is, in adapting these films the first thing that I do is I try to figure out what the movies made me feel and why, and then create those same feelings in you by telling you a different story."

Hawley, acclaimed for his inventive takes on Fargo and the X-Men realm through Legion on FX, is celebrated for weaving original narratives that retain the essence of their source material while introducing fresh characters and environments.

In the debut live-action television series situated within the Alien universe, Hawley maintains his pattern of elevating the source material through his distinctive creative narrative approach and macabre wit.

Nevertheless, for an eight-episode series to stay engaging, the Emmy-acclaimed screenwriter required the introduction of several fresh components that might divide Alien devotees.

"The one feeling you can't produce in an audience is the discovery of the life cycle of the Xenomorph," he explained.

"We all know it, right? And so that genetic revulsion that you felt at every stage is a little muted.

"So, the only way to produce it is to create new creatures that you don't know how they breed, or what they eat. Every moment, seeing it crawl down the back of your shirt or in your helmet, the feeling comes back that's such a seminal part of Alien.

"So, that's why I introduced them. It was almost function over form.

"We spent a lot of time in the writers' room just trying to gross each other out as to what was worse. The one-upmanship was profound."

Naturally, the legendary Xenomorph is anticipated to command centre stage predominantly, though enthusiasts will shortly discover the cosmos harbours numerous other terrors capable of orchestrating mankind's demise.

Alien: Earth premieres Wednesday, 13th August on Disney+.

For a limited time only, witness the first stage of the life cycle of the Xenomorph up close with a thrilling new display at London's Natural History Museum.

Visitors can touch real pieces of the solar system at the Museum's blockbuster exhibition, Space: Could Life Exist Beyond Earth?, and discover more about one of pop culture's most iconic and frightening creatures just by the entrance until Friday, 22nd August.