As we all know, most consider Ko-Guy to be a C - F tier character, and one of the worst in the game. It mostly stems from it's lack of options(In my opinion) and I feel like it doesn't have much combo diversity at the moment. It's always just  3m1, Clever, Crushing Jaws, Fluttering Pounce, Wing Throw, Black mucus. So I have a few changes in mind but he might even need more.

He need to be able to uppercut into Fluttering Pounce, it would very much help him improve his versatility, and combo diversity. Allowing him to not completely rely on Crushing Jaws to start air combos, which can only go into Wing Throw right now. This is definitely one of the most important changes.

Crushing Jaws should get an air variant. This would rely on the first change to start an air combo, and would allow for another aerial combo route while Wing Throw is on cooldown. I propose it to be the normal 3 bites into a Supplex, slamming them onto the ground doing ragdoll similar to the end of normal Crushing Jaws.

Black mucus should have less windup and longer ragdoll, this would help it become a better neutral option, allowing him to be more then just an m1 merchant after all these years.