Deoxys is an extraterrestrial, bipedal Pokémon with four distinct forms, each emphasizing a different stat. Common features across all forms include a predominantly red body, a light blue face, and three light blue dots on its back arranged in a triangle. Typically, there is a purple stripe down the center of its face and a purple, crystalline organ in its chest. Its eyes are white and circular, set within rectangular black sockets. Some Deoxys seen in the anime have a green crystalline organ and facial stripe.
Deoxys was created from a space virus mutation. This Pokémon is highly intelligent, with its brain seemingly located in the crystal in its chest. This organ can emit laser beams. In the anime, it has shown the ability to regenerate lost body parts during battles and create auroras without changing form. These auroras have varying electromagnetic wavelengths used for communication among Deoxys. Electromagnetic waves from people, Pokémon, and electronics can interfere with its vision and communication. Deoxys arrived from outer space inside a meteor, and its various forms possess unique abilities and techniques.
In the anime and manga, Deoxys has been depicted creating clones of itself. These clones have lifeless eyes, duller colors, lack the characteristic chest crystal, and remain in Normal Forme. They cannot morph their tentacles into hands. When defeated, these clones dissolve into dust-like particles.
Forms
Deoxys has four forms: Normal Forme, Attack Forme, Defense Forme, and Speed Forme.
Normal Forme
In Normal Forme, Deoxys has tapering legs with a segmented, vertical, blue stripe on the upper portion. The abdomen is black with vertical lines, while most of its skin is reddish-orange. Its arms can take different forms, usually coiled tentacles in a double helix, one in its primary skin color and the other light blue. Alternatively, it can form humanoid arms with a red top and blue underside, ending in five-fingered hands. This form has blunt protrusions with a single blue stripe on either side of its head and a stubby tail.
Attack Forme
In Attack Forme, Deoxys's legs remain tapered but now feature unsegmented blue stripes running the entire length, with a large spike on the knee. It has two pairs of whip-like tentacles with pointed tips, one reddish-orange and one blue, replacing the previous coiled tentacles. The head protrusions are triangular, with an additional one extending from the top of its head. Most of its reddish-orange skin has receded, revealing a striated, black chest and abdomen. Its tail is longer and more pointed.
Defense Forme
In Defense Forme, Deoxys has bulky, wide legs that are somewhat flat at the ends with bluish-green spots on each knee. It retains its two pairs of red and blue tentacles, now flat and broad. The head has fused with its body, eliminating all protrusions, giving it a helmet-like appearance. The reddish-orange skin covers the entire body, hiding any inner black portions. There is a single blue stripe on each shoulder, and its tail has disappeared.
Speed Forme
The Speed Forme has a sleek black body with thin striations. Reddish-orange skin covers only its head, hip joints, and the area around its crystal. There is now one tentacle on each side of its body, one red and one blue. The head protrusions point upward, and the back of its head forms a long spike with a thick blue stripe running down its center. Additional blue stripes appear on the hip joints and legs.
(Source: Bulbapedia)
