Xenomorph

The Xenomorphs (AKA Aliens) are endoparasitoid extraterrestrial species that are one of Thomas and Twilight's toughest, and baddest enemies.

Trivia

 * Thomas, Twilight, and their friends will first encounter an Xenomorph in Thomas and Twilight Sparkle's Adventures of Alien.
 * Thomas, Twilight, and their friends will soon face more of them in Thomas and Twilight Sparkle's Adventures of Aliens.
 * Thomas, Twilight, and their friends will soon encounter another one in Thomas and Twilight Sparkle's Adventures of Alien 3.
 * Thomas, Twilight, and their friends will face even more of them in Thomas and Twilight Sparkle's Adventures of Alien: Resurrection.