D-Rex is the boss of Sigma Stage 3 in Mega Man X. It was supposed to be a destructive weapon with about 30 meters length based on the T-Rex (hence the name), but by the time that Sigma's hideout was invaded by X, only the head was completed, so it was converted into a tank-like Mechaniloid to be used against him.[1] Due to its outstanding performance, REX-2000 was developed on the basis of D-Rex.[2][3]


Mega Man X

D-Rex's top can detach from the bottom, hovering in the air, and both try to crush and seriously damage X. The bottom can be stood upon, but if X stands there for too long the top will try to crush him. When either section collides with a wall, it can daze X and knock him off. Both sections can also charge up massive electron spheres that inflict devastating damage. Its main weakness is the Boomerang Cutter.

  • Body Slam (体当たり): D-Rex rushes to strike the player with its body. It can separate its top to attack midair, while its bottom attacks along the floor.
  • Sandwich (サンドイッチ): D-Rex drops its top half in an attempt to sandwich the player if they are standing on the bottom half.
  • Electric Shot (電撃弾): D-Rex charges a giant sphere of electricity between its halves, then fires it at the player's position.


D-Rex (Command Mission)

In Mega Man X: Command Mission, the D-Rex is a common, but powerful, enemy that appears in the Vanallia Desert. This D-Rex is a brownish-grey and is more dinosaur-like in appearance. D-Rex attacks with shots, Heterostorm and releases explosive miniatures called Mini Rex. Mini Rex can be prevented if D-Rex's jaw is broken with at least 11 C-type attacks.

Run away in his third turn onwards after being damaged by 11 C-type attacks. Trickstar and Stealth Mode take damage of Mini Rex.


D-Shark is a weaker and more colorful version of D-Rex found at the Tianna Camp in Mega Man X: Command Mission. D-Shark attacks with Ultra Blizzard and releases explosive miniatures. Mini Shark can be prevented if D-Shark's jaw is broken with at least 3 C-type attacks. Trickstar and Stealth Mode take damage of Mini Shark.

A D-Shark is available from the beginning in the Deployment Center.

Other media

Archie Comics

When Sigma-1 built an army of Mavericks to defend his base on the Lost Hex in Worlds Unite, the D-Rex appeared alongside such constructs as Eregion, the D-1000, Raider Killer, and the Shadow Devil.



  1. Kodansha Manga Hyakka 6: Rockman & Rockman X Daizukan
  2. Kodansha Manga Hyakka 34: Rockman X Chō Hyakka page 56
  3. Page 104, "Rockman X4: the Strongest Grand Pictorial Book" (ロックマンX4 最強大図鑑)