Original Gastrea

The Original Gastrea was an unnamed Gastrea that invaded the Tokyo Area. The owner of its original human body was hired by Kikunojou Tendo to retrieve the Legacy of the Seven Stars from the Unexplored Territory, but was attacked by a Gastrea and succumbed to Shape Corrosion. Kikunojou was forced to hire Kagetane Hiruko to retrieve the case from the Gastrea, sparking the events of the Civil Security arc.

Appearance
The Original Gastrea is a Stage I spider type with four, slim legs and a hefty abdomen. Its legs display several different patters. The Original Gastrea possesses eight eyes and a pair of fangs. The Gastrea's most prominent components are two horns appearing next to its fangs and elongating to the middle of its legs.

Civil Security arc
After entering the Tokyo Area, the Original Gastrea manages to invade Sumiaki Okajima's home and, whilst the man speaks on the phone, ambush him and pass the Gastrea Virus onto him.

Legacy of the Seven Stars arc
Two days after its initial attack, the Original Gastrea knits its own web into a kite and, now located in the Outer Area—32nd Area, glides through the air as Rentaro Satomi and Enju Aihara are aboard a plane. Once Rentaro notices the Gastrea, he quickly tells the pilot to lower their altitude. However, before he can do so, Enju opens the back door and jumps out of the plane and on top of the Gastrea. The Original Gastrea is then taken down to the ground, where it regains its former size and confronts Initiator Enju Aihara.

However, much to its demise, and after putting up a short-lived resistance, the Original Gastrea is mortally crushed by Enju. Not long after, the case in its belly, containing the Legacy of the Seven Stars, is taken by Kagetane Hiruko and Kohina Hiruko.

Abilities
Evolutionary Jump (進化の跳躍 Shinka no Chōyaku): The Original Gastrea gained the ability to knit its own web into a kite, using it as a form of transportation.

Growth: An ability which granted the spider-type astounding flexibility; permitting for extreme size reducement. The Original Gastrea was able to decrease its body size tremendously to allow for a breezy escape, successfully being able to conceal its presence from the monitoring cameras. The Gastrea was also able to change its size to match that of a small kite, allowing for aerial transportation. The rate at which the Gastrea can change its size appears to be particularly fast.

Enhanced Strength: With a single hit of its eight legs, said Gastrea was able to push Enju away from it while at the same time preparing its next attack.

Enhanced Durability: The Original Gastrea was able to withstand a direct hit from Enju Aihara whilst in midair.

Trivia

 * Although it has been referred to as the "Original Gastrea" (感染ガストレア Kansen Gasutorea), the character's name remains unknown.

Battles

 * Enju Aihara vs. The Original Gastrea