This plant is Euphobia Lactea Crest and as you can see it has been grafted onto another Ephobia. In the wild the crest is rare but with breeding and propagation techniques they are easily found. The Euphobia Lactea Crest is grafted onto the Ephobia to speed up it's growth. I've been told they do this in Thailand.
I'm not really into Cacti. Repeat after me, All cacti are succulents but not all succulents are cacti. I have some and enjoy them but there are endless varieties of succulents to discover. The Coral Cactus, though, is a beauty and I'm looking forward to seeing it flower.
I originally posted this pic on other site and realized it made it look larger than it really is so I took another picture with a yardstick to show how large it really is.