Did the Buddha ever delve on the dangers of one's own spirtual achievements feeding the ego?

This question came up when I really thought back on both my and many others' spiritual journey. In the New Age community, especially, the sense of viewing things as illusions and making progress in one's spiritual path can easily steer you to be more condescending or arrogant (i.e viewing others as somehow lesser or more immature than you) and in the process, feed the Ego. Often you see this in spiritual teachers as well, who seemed to have, in their journeys to eliminate the Ego, fueled their Ego. Did the enlightened Buddha ever touch on this subject?