Melt the chocolate by adding chocolate chips and coconut oil to a small bowl and microwaving for about one minute until fully melted.
Assemble the spiders by breaking three pretzel sticks in half, twisting apart the Oreo cookies, and inserting the pretzel sticks into the cream side as legs. Drizzle melted chocolate over the legs and place the blank Oreo wafer back on top.
Decorate the cookies by dipping one side of each assembled cookie into the remaining melted chocolate, adding candy eyeballs and sprinkles on top.
Set the cookies in the fridge for at least ten minutes to allow the chocolate to harden.