One of the really spectacular species Haworthia reinwardtii is a stemless species and will form a clump over time. So if you are looking offsets for propagation be patient.
The deep green to nearly black foliage color is influenced by light intensity and moisture, so you will see a degree of variation in color.
The individual leaves are a triangular shape, over time a single plant can reach 60cm in height. Offsets will occur after 2 - 3 years.
Best grown in a container and as with most succulents grown as specimens you can consider adding some form of pebbles to the top of the growing medium. These not only highlight the plant itself but will protect the foliage from any dirt splashed by water.
Flowers are pale cream to white, tubular and bell shaped appearing during late spring.
Haworthia reinwardtii will produce produce offsets. Some growers like to keep a single plant, others prefer a clump.
However eventually you will need to divide them. Re plant in a succulent potting mix, water well once and they will usually grow well.