Rhodactis Mushroom come in all shapes and forms. But these Wagonwheels are some of my favorites. These are the hard-to-find red/blue variety
 
Vincent Chalias over at ReefBuilders wrote a great article on these.... -  Rhodactis bryoides

Only got 2 available
 
Care Level: Easy
Lighting Requirements: Low to Mid
Water Flow: Slow to Moderate
Placement: Rockwork