Line a large tray with parchment paper and set aside. Gently separate the oreos by slowly twisting them apart. (Some will break, it's okay, just try to be gentle)
Separate the green candy melts into 3 parts (this is to keep it from getting hard while you decorate) and place each section in a microwave safe bowl.
Add about 1/2- 1 full teaspoon vegetable oil or shortening (more if needed to thin it even more).
Melt in 20 second bursts in the microwave (Microwave 20 seconds, stir 20 seconds, etc.)
Be patient when melting and stir well in between bursts to avoid burning the candy melts.
Dip one end of the lollipop stick into the melted chocolate and press that side into the cream side of the oreo. Press the pretzel stick into the top of the cream on the oreo.
Place the other half of the oreo on top and gently press and hold. Let harden.
Spoon the melted green candy melts chocolate over the oreo pop evenly being careful to avoid the pretzel. Gently tap the oreo pop on the edge of the bowl to get the chocolate to cover the oreo evenly.
Press two edible candy eyes into the oreo pop and then sprinkle green jimmies above the edible eyes.
Transfer the oreo pops to the prepared tray and allow to harden completely at room temperature.
Once hardened, use the black edible gel to draw on a crooked "smile" for the Frankenstein. Place in the fridge or freezer to allow the gel to harden before placing into a oreo pop stand/holder.