Place the drained cans of peaches, pineapple chunks, fruit cocktail, and mandarin oranges in a medium-sized mixing bowl.
Add the cool whip and gently fold until the fruit is completely coated. If you need to add a bit more cool whip, add a spoonful or two at a time until all the fruit is coated.
Gently fold in the mini marshmallows.
Store in the fridge until ready to serve.
To serve, scoop individual servings into bowls and garnish with a maraschino cherry if desired.