Leaves are distinctive, 50-55 cm long by 22-28 across, broadly ovate, silvery blue, and distinctively cupped in the upper surface. Leaves have small hooked teeth along their margins and 2.5 cm long dark grey terminal spine. It is not unlike other agaves, though whale tongue leaves are sculpted, with a gutter down the center which is ideal for collecting and funneling rain to the roots.
The flowers are pale yellow-green, borne on a towering stalk at the end of its long, beautiful life.
It is one of the most beautiful century plants.