Crush the Oreos until they turn into fine crumbs (mixer or food processor).
Then cream together crumbs with the softened cream cheese (electric mixer works good for this part).
Form the mixture into small balls (smooth as possible). Place on cookie sheet lined with parchment paper.
Freeze the balls for 30-60 minutes.
Melt the candy melts in small microwavable cups. Read package instructions for details.
Place balls (cold or frozen) into the melted candy. Use a fork and skewer to hold the ball and then dip into the melted candy.
Place the ball/truffle back on the cookie sheet. Decorate with candy eyes, colorful nonpareils, confectionaries, etc. while still still wet.
TIPS for "chocolate" candy melts:
Melt candy melts (Wiltons or similar brand) in the microwave.
Read the directions on how to melt. When "chocolate" candy melts, it is ideally a smooth mixture.
However, if it comes in contact with water, it will “seize” or turn into a grainy, clumpy mess.
If you melt the candy too long (overheated), it will be thick and lumpy.
Pay close attention to the instructions and you'll melt these candies just fine.