Padaung
Population: marginal, Origin: Thailand
The Padaung are a sub-group of the Shan, who aren't entirely considered minorities as they have always occupied the areas of northwest Thailand and the Shan states of Myanmar. The Shan speak a dialect similar to Thai and are even known as Thai Yai, having been assimilated into Thai culture.
There are pockets of Padaung around Mae Hong Son. The Padaung attract many curious visitors on account of their long-necked women. A tradition of beautifying women by adding brass rings to their necks has been preserved largely for generating tourism. Although the neck appears cruelly elongated, it is the collarbone which has been depressed rather than the stretching and weakening of the neck.
There are some lesser tribes which you are unlikely to see on mainstream tours; however, they historically play a significant role in the area. The Lua were original inhabitants of Northern Thailand. They speak a Mon-Khmer language, which differentiates them from the other hill tribes, which mainly speak Tibeto-Burman languages. Their villages are much more isolated in comparison to other hill tribes and there is less of a chance seeing them. However, along the Chiang Mai-Mae Hong Son border, you may see women with many tiny orange bead necklaces walking to market