From Halopedia, the Halo wiki
The Gigas is capable of being outfitted with a huge range of munitions, though is most commonly deployed with two subwave-guided micro-plasma torpedo launchers and two incendiary plasma mortar launchers. The cannon mounts alone are described as the size of an F-29 Nandao.
The Gigas-class world striker earned its nickname during its first usage centuries ago. An unidentified civilisation in the Karava region of space refused to bow to the Covenant's dominion, and as such three hundred Gigas strikecraft were deployed to raze the world in a total genocide.
Despite the age of this craft, the mouthpiece in the most recent model of Sangheili Flight harness is still equipped with the multi-port required to interface with them. During the Human-Covenant War, Gigas fighter-bombers were carried by the Fleet of Swift Justice. At the end of the Battle of Netherop, one of these strikecraft destroyed the Steadfast Strike.
"Gigas" is a Greek term for "giant." It is the root of the word "gigantic".
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