Place the popped popcorn in a large bowl and remove any unpopped kernels.
Melt the green candy melts in the microwave in 30-second bursts, stirring between each until smooth.
Pour the melted candy melts over the popcorn and stir gently until most pieces are lightly coated.
Add the mini marshmallows and stir again to distribute them evenly through the mix.
Spread the coated popcorn onto a parchment-lined baking sheet and let it set for 10 minutes.
Sprinkle the candy eyeballs and Halloween sprinkles over the top, then toss lightly so they stick to the chocolate.