Melocactus azureus v. ferreophilus Cactus They have some of the

They have some of the biggest spines of any Gymnocalycium

Plant has 5 growing points

Tacitus bellus  AKA Graptopetalum bellum

Color is also better in cooler weather (that's normal for most Aloe hybrids)

Echidnopsis nubica  An uncommonly seen species from Sudan which has the tiniest flowers of all Stapeliads

Melocactus azureus v. ferreophilus Cactus They have some of theMelocactus azureus var. ferreophilus This is a nice cephallium forming species with green to blue green skin. It looks and grows like normal cactus several years but once it gets big enough the main plant stops growing but produces a large hairy inflorescence that continues to grow for the rest of the life of the plant. Eventually the inflorescence can be taller than the plant itself. This is more tropical than most succulents so it doesn't like cold