Crassula barklyi - Rattlesnake Tail
While Crassula barklyi is also known as "Rattlesnake Tail" and "Bandaged Finger" (no joke!), these little compact towers are definitely not dangerous. These are very slow growing, and they send up lots of branches from the base so eventually you get a cluster. They stay pretty short (max 4"), and occasionally produce a flower from the top of the stem. The flowers smell AMAZING you guys. It is monocarpic, so the stem that made the flower does die, but it will leave you with plenty of offsets so you won't lose it from your collection. Originates from Lesotho, Namibia, South Africa, and Swaziland.
These can handle a wide range of light levels, from mostly shade to mostly sun.
Current batch looks like LAST pic. Some have a dead flower head and some don't. There are plenty of offsets to keep going when the main stem dies off.