I just happened into a group of websites describing some monasteries in Thailand called Buddhist

[vlyons]

4. You probably saw images of "wrathful deities."

which are projections of your (or somebody's mind). I have been taught to think of them as "peacful-wrathful" deities, because it is my mind that turns them into peaceful protectors of my own calm abiding mind. Assuming of course that I (or anyone) can mentally calm down into a serene and tranquil state, when scary and adverse thoughts and circumstances come our way. If you are still confused about these images, you should talk to Tibetan Lama or some authentic teacher in Thai Buddhist tradition. The peaceful-wrathful deities are part of Vajrayana Buddhism, which is a secret and oral tradition. Secret because people, who have not been instructed properly get all kinds of erroneous notions. Many Westerners think it is some kind of devil worship, which couldn't be further from the truth. I don't talk much about Vajrayana for that reason. Plus I'm not qualified to teach it.