Big Willy is a giant mech of the toddler mascot of Pox's Big Willy Restaurant, who was playable in Destroy All Humans! Big Willy Unleashed. This living weapon was made by Orthopox and has comparable strength to the Saucer. Big Willy, by physical standards, was invulnerable thanks to a special alloy in his armor and was superior in strength. Big Willy's only weakness is his battery: His battery always runs down slowly, and also represents his ammo for his weapons that use it up at varying speeds. Thankfully, in the event the Big Willy runs out of battery, it can be recharged by electrical weapons, the Zap-O-Matic or Ball Lightning.
Regurg-A-Tron: The first weapon equipped to Big Willy was the Regurgitron. It allows Big Willy to spew acid from his mouth in order to destroy whatever is in front of Big Willy. It's Big Willy's worst weapon, it's weak, it can't destroy buildings, and puts Big Willy at a screeching halt. Although it hardly uses any battery.
Heat Ray: No Robot Mech would be complete without laser eyes! The Heat Ray drains the battery greatly under prolonged use, it is the only Big Willy Weapon that can be aimed, and is usable while moving.
Windbreaker: The most powerful and most hilariously outrageous weapon of all which enabled Big Willy to let it rip: The weapon spewed out tons of corrosive material from Big Willy's behind in a huge wave all around the mech. With the look, sound, and placement of the weapon, it actually looked as though Big Willy farted. That weapon destroys buildings on contact, akin to the Quantum Deconstructor. This weapon does drain a huge chunk of battery every use however.
- Vom-I-Tracking Sweep: Maximize Regurg-A-Tron damage
- Gamma Ray Implosion: Maximize Heat Beam damage
- Methane Hyper-Compression: Maximize Windbreaker damage
- Bi-Lithium Ion Packs: Decrease the amount of time it takes Big Willy's batteries to recharge
- Antiphoton Energy Converter: Minimize the amount of time it takes Big Willy's batteries to recharge