I purchased this cactus several years ago from an Ebay vendor because of its cristate form. The globe shown in this photo is one of the new heads that have appeared in the last couple of years.
Usually cristate forms are more sensitive to temperature extremes and sunlight than normal forms, but nothing seems to affect this cactus. I rarely water it so it has to get by on whatever rainfall we have. It seems extremes suit this specimen, despite the cristation.
To see the large crested portion of the cactus, check out my previous post on about it.