Thin Man (EU2012)

The Thin Men are agile, quick, and elusive alien creatures. Designed to look human so that they can successfully infiltrate society, Thin Men are responsible for handling the more secrative operations of the alien invasion. (Though some aren't exactly subtle, such as planting huge alien bombs in the middle of urban centres.)

XCOM commanders won't have much trouble finding them however, as they are usually caught in the act of whatever their mission may be.

In standard abduction missions, they will rush for cover when discovered. Their great mobility can be quite annoying as they will often be able to run right up to your troops before firing. Their overall accuracy is quite poor though and their health is nothing remarkable. Beware of their poison spit though, this will decrease your soldier's aim and steadily remove health by one point each turn. Keep a medkit handy where you can as this will remove the poison. Also beware of their leap ability. Keep snipers supported by other XCOM troops so they are not caught with no action points when a Thin Man leaps up to them.