Caviar, known as Malware in English localizations, is one of the Four Dark Warriors (Four Heavenly Kings) of the antagonistic Death Metal Empire. He oversees prison-like facilities for Zoids research and experimentation under Emperor Gigaboss's command. Caviar operates from bases equipped with trapdoors resembling his pointed teeth, using them to dispose of failing subordinates by dropping them into his Zoid's enclosure below.

Ruthless and sniveling, Caviar favors deceit over direct combat, relying on traps, psychological manipulation, and technological enhancements to his Zoid. These underhanded tactics often prove insufficient for decisive victories despite his formidable nature, making him the first of the Four Dark Warriors to be defeated.

His primary Zoid partner is the alligator-type Gabriator (also called Overbyte or Gabrigator). Caviar repeatedly upgrades this machine with experimental weaponry and defenses, but the enhancements consistently fail to secure lasting advantages, resulting in the Gabriator's frequent combat failures.

Caviar maintains a notable operational relationship with fellow Dark Warrior Drake, immediately contacting him for reinforcements when his facility is attacked. His Japanese name, Caviar, follows the Death Metal Empire's food-themed naming convention, while his English name, Malware, aligns with the faction's IT terminology. Early concept art depicts him holding a crocodile plushie, hinting at an idiosyncratic personal habit.

Caviar appears exclusively as an antagonist in the main *Zoids: Wild* anime series.