In small microwavable bowl, microwave chocolate chips uncovered on High 30 to 60 seconds, stirring every 15 seconds, until melted and smooth. Spoon melted chocolate into 1-quart resealable food-storage plastic bag; cut tip from 1 corner of bag. Pipe 8 spider legs onto cooking parchment or wax paper-lined cookie sheet. Freeze about 15 minutes.
In large bowl, beat cream cheese and powdered sugar with electric mixer on medium speed until smooth and creamy. Add pumpkin, pumpkin pie spice and 2 containers of the Greek yogurt. Beat on medium speed until blended. Pour mixture evenly into 10- to 12-inch wide shallow serving dish.
Spoon 1/4 cup of the remaining Greek yogurt into 1-quart resealable food-storage plastic bag; cut tip from 1 corner of bag. Pipe yogurt to make spiderweb design over top of pumpkin mixture. Reserve remaining yogurt for another use.
Place malted milk ball on top of dip for spider body. With melted chocolate, attach 2 eyeballs to malted milk ball for eyes. Arrange chocolate spider legs around malted milk ball.