Melt butter in large saucepan

Add marshmallows to saucepan and stir continually until smooth and runny

Remove from heat and add green food dye to mixture. Stir until color is incorporated. 

Pour Rice Krispies into a large bowl. Pour green marshmallow mixture on top and mix until cereal is coated

Give the mixture a few minutes to get sticky, this will make the ball making process easier. 

Form the mixture into small balls and allow to set on a nonstick surface (baking sheet coated with nonstick spray or wax paper). I used a mini muffin tin to create a uniform size to the treats.

While the treats are still fairly sticky, add candy eyes to the balls. The marshmallow should keep the eyes on without needing any other glue. 

Give them 30ish minutes to set, and you're good to go!