Agave pumila is a very nice, and hard to find, dwarf species.
very thick, triangular blue leaves that become a lighter color as the plant matures.  Single rosettes grow to 12-18 inches high and wide.    Because of its compact size, it can easily be kept in a pot.
This is a beautiful, specimen size A. pumila.  Sale plant is the actual one in the photos.
 
Full sun in mild climates to part shade.
Well-drained soil and infrequent water.  
Hardy to approx. 25-30 degrees F.  
USDA Zones 9b-13b
Pot size: 1 gallon
SHIPPED BARE-ROOT