Divide Creamy White Frosting in half. Tint one portion of frosting using green food coloring and the remaining portion of frosting using blue food coloring.
Spoon blue frosting into a decorating bag fitted with a petal decorating tip (such as Wilton brand #103). Pipe blue frosting onto tops of cupcakes to resemble waves.
Spoon green frosting into a decorating bag fitted with a large round decorating tip. For each alligator face, pipe two large mounds of green frosting at the top of each cupcake; top with two smaller mounds. For snout, pipe a wide strip of frosting from the top two mounds toward the bottom of the cupcake, ending with a large mound. Top large mound with a smaller mound for nose.
For eyes, cut marshmallows in half. Poke a small hole in the smooth side of each half and insert a chocolate piece for a pupil. Press eyes into position on face. Insert two chocolate pieces into end of nose for nostrils. For sharp teeth, cut gum into small triangles. Press teeth into position on nose.
Decorating bags Petal decorating tip (such as Wilton brand #103) Large round decorating tip
In a large mixing bowl beat shortening, vanilla, and almond extract with an electric mixer on medium speed for 30 seconds. Gradually add about half of the powdered sugar, beating well. Beat in 2 tablespoons of the milk. Gradually beat in the remaining powdered sugar and enough of the remaining milk to reach spreading consistency.