Event 23: Slippy's Invention
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The player is faced against Fox and Falco on the Venom stage, but Fox and Falco are both equipped with a permanent Cloaking Device, said to be invented by Slippy, Star Fox's mechanic. As a result, they are more difficult to see. Although they are invisible, Fox and Falco can still be damaged (akin to an Invisible Melee).