Feel a shiver down the spine as you gaze at the deity? The fearsome figure - astride a buffalo with menacing horns - is Lord Yamadharma, the ultimate arbiter of your life here and hereafter. Facing the south, in one hand he holds the ankus to guide his black mount; the other grips the whip with which he draws you at the destined moment to the other world. His silver plated eyes have an implacable gleam.
Beside him stands his eternal attendant Chitragupta, with the palm leaf and quill in his left and right hands. He records all human actions, and recites his findings on the day of reckoning. Yama delivers the verdict of reward or punishment.
The God has strong likes and dislikes. He will not tolerate black thread or cloth. Coconuts must be offered whole, and no jasmine is allowed in worship. His colourful garland twines oleander, tuberose and basil.
The circle is sacred to him as we see in the architecture (outer wall, dome, inner dais). He accepts tulabharam (generally banana or jaggery) and the special 101 padayal (offering) of ashball, raw rice, panakam and buttermilk...
It's very interesting to me, these specifics of the god's likes and dislikes: generally one breaks a coconut before offering it, for example. Every temple distinguishes itself from every other by some quirk like this. The article goes on to say that you must never clasp your hands behind your back in Yama's presence!
Yama is a Vedic god, one of the most ancient; he has become otiose. He has been described as the first man, the first to die and find the way to the otherworld. After he died, his sister Yami's grief was so intense that the new universe was disturbed. In the endless day of the beginning the gods created night, so that days could pass, and time and sleep would help Yami to forget. A boon for which we can be grateful.