Line cookie sheets with waxed paper. In 2 (1-quart) saucepans, separately melt vanilla candy coating and chocolate candy coating over low heat, stirring each constantly, until smooth.
Ghost cookies will be dipped in vanilla coating; bug cookies will be dipped in chocolate coating. Coat and decorate a few cookies at a time as coating sets up quickly. For each ghost or bug, place cookie in coating; lift out with fork, letting excess drip off. Place cookies, coated side up, on cookie sheets.
For each ghost, place 2 miniature chocolate chips on each coated cookie to resemble eyes and 1 regular chocolate chip for mouth. Let stand 10 minutes until set.
For bugs, cut pretzels into curved pieces for legs. Dip one end of each curved piece in chocolate coating; place 3 legs on each side of each cookie. Cut 2 short pieces for antennae. Dip one end of each pretzel piece in coating; place 2 antennae on top of each cookie. Place 2 candy-coated baking bits near antennae for eyes. Let stand 10 minutes until set.