Note: “(Rare!) 未使用アナウンサー音声クリップ | 大乱闘 スマッシュ ブラザーズ ＤＸ：ザアナウンサー云う: "ギガクッパ” (Audio Rip)” means: “(Rare!) Unused Announcer Voice Clip | Great Fray Smash Brothers Deluxe: The Announcer Says: “Giga Koopa” (Audio Rip)”
I know TetraBitGaming has already posted the “Giga Bowser” voice clip on his YouTube “Lost Bits” video with an audio rip, however, that was the English version of the announcer saying “Giga Bowser”, and NOT the Japanese version, which is “Giga Koopa”.
Disclaimer: You can’t find this with an audio rip anywhere else on YouTube, so this is the only place where you can find a Japanese voice clip of the Announcer saying “Giga Koopa” with an audio rip.
By the way, sorry for about the quality. This screenshot/picture I took a while ago is *very* old.