Tripod stance

Meerkats adopt a range of postures while watching for predators. One individual (left) has 4 limbs in contact with the ground, another (middle) has only 2 limbs and the tail in contact, and another (right) is standing erect on its 2 hind legs and supported by the tail.
Kangaroos can stand erect on their hind legs, supported by their tail as the third leg of a tripod (they can even balance on their tail alone).
Kangaroos use "pentapedal locomotion" while grazing. In this gait, the tail and the forelimbs form a tripod while the hind legs are being moved.

A tripod stance is a behaviour in which quadruped animals rear up on their hind legs and use their tail to support this position. Several animals use this behaviour to improve observation or surveillance, and during feeding, grooming, thermoregulation, or fighting.[1]

  1. ^ Hickman, Graham C. (December 1979). "The mammalian tail: a review of functions". Mammal Review. 9 (4). Wiley: 143–157. doi:10.1111/j.1365-2907.1979.tb00252.x.