Indeed, the plant can be invasive; but just this quality can make it an effective groundcover, if you don't mind it taking over. Although not grown for its bloom, lamb's ears does produce light purple flowers on tall spikes. It is grown for its silvery foliage, which has a velvety feel to it. The shape and feel of its leaf readily explains how lamb's ears got its name. Lamb's ears plants are deer-resistant; apparently it is this same velvety feel that makes lamb's ears unpalatable to deer.
An herbaceous perennial, lamb's ears reaches only about 1 inch in height (with a similar spread). Planting zones 4-10. Lamb's ears grows best in full sun.