Of all the domestic animals, the elephant is certainly one of the oldest known, if not the oldest.
In Hindu mythology, Ganesha, the elephant-headed god, is one of the deities associated with wealth.
Therefore, unless the dreamer himself has a personal anathema towards elephants, dreaming of an elephant is always a harbinger of great good fortune.
If the elephant is friendly and happy, expect a change in your luck for the better.
If the dreamer was riding an elephant, this indicates a rise in social status.
A performing elephant augurs new friends, while a working elephant hints at success through your own efforts. Even an angry or frightened elephant, or even if they attack you, is not all that bad an omen.
It only implies delays in the attainment of your goals.