AI weapon (Peace Walker Project)

The AI Weapons were mechanical vehicles that, as the name implies, were completely automated. There were 4 AI weapons: Pupa, Cocoon, Chrysalis, and Basilisk, reflecting Hover, Tank, Flight, and Walking, respectively. Pupa, Cocoon, and Chrysalis were prototypes to Basilisk.

They were develop by both Huey Hemmerich, responsable for developing the 3 prototype weapons and Basilisk, and Strangelove, AI researcher who develop the AI Reptile Pod and the more advanced Mammal Pod for Basilisc; under the directive of Hot Coldman for the Peace Walker Project.

All of the AI weapons contain a Reptile Pod; an AI module that allows the AI Weapon to follow basic commands. Basilisk, however, was different in the sense that it contained an extra AI called the Mammal Pod that was used to calculate the chances of a nuclear attack, and based on the data (true or false), it launches what it believes to be a retalitory nuclear weapon over to the nuclear threat.

Big Boss and the Militaires Sans Frontieres encountered each of these devices when trying to investigate an armed force belonging to the CIA that was sending Nukes into Costa Rica.

For unknown reasons, whenever Big Boss or one of his comrades managed to rip out certain key components to the AI pod in Pupa, Cocoon, and Chrysalis (and in the case of the upgraded versions, Basilisk as well), the AI pod, when detached, launches itself into the sky in a similar fashion to a Rocket.

After the events of the mission, Big Boss and the Militaires Sans Frontieres used parts salvaged from the AI weapons to create Metal Gear Zeke.

Trivia

 * The names of the AI Weapons, Pupa, Cocoon, and Chrysalis, are all stages of a butterfly's life cycle. In fact, Basilisk is referred to as Butterfly.
 * The AI's that controls the prototype AI Weapons was called GW, TR, and TJ just like the proxy-AI system used to run and govern The Patriots time later.
 * All four AI Weapons have the ability to talk and sing. Basilisk (AI Pod) speaks with The Boss's voice.

Behind the Scenes

 * After completing the game, Extra Ops allows Snake and/or other MSF personnel to fight upgraded versions of the AI weapons. Other than their harder difficulty, a notable difference between the original and upgraded versions are that the upgraded versions are almost completely red.