The century plant does not really take a century to bloom but it does take 12 to 25 years depending on the conditions.  With more rainfall, the blooms will occur more often than in a dry desert area.  It is very drought tolerant but requires a lot of space. It will also produce many new plants near the base of the mother plant.  It is blue-green in color and has lots of spines.  The deer will definitely leave this one alone.  You will often see this planted at entry gates to ranches and other large properties.