Line a sheet pan with parchment paper and place half of the graham cracker squares onto it.
Place 2 marshmallows and 2 teaspoons of chocolate chips over the graham cracker squares.
Either by using a torch or a short time under a broiler, partially melt the marshmallows.
Immediately place the top halves of the graham crackers over the still-warm marshmallow and chocolate filling.
If making these as pops, press a popsicle stick into the center of the marshmallow layer, leaving the handle exposed.
Place the assembled sandwiches into your freezer for 20 minutes.
Meanwhile, place plant milk into a stand mixer bowl and sift the powdered sugar on top of it. With a whisk attachment, mix the glaze until thick and smooth. Gradually add green food coloring while the mixer runs to reach your desired tint of green.
Carefully and generously coat each sandwich with the green coating, using a spoon or offset spatula to help cover all sides, without getting it all over the popsicle sticks. Let excess drip off before placing each sandwich onto a wire rack.
Press 2 candy eyes into the upper third of each sandwich while the coating is still tacky.
Break the pretzel sticks in half and insert each half into each side of the sandwich. Transfer back to the freezer to set.
Meanwhile, melt the vegan chocolate chips in a clean double boiler. Let cool until thick enough to pipe without running.
Transfer the melted chocolate to a piping bag fitted with a very small round tip. Pipe a mouth, hair, and maybe some forehead stitches onto each face. Refrigerate the sandwiches until fully set. Remove from the refrigerator a few minutes before serving.