Bipedal
Upright two-legged stance and locomotion, freeing forelimbs for grasping or powering explosive leaping strides.
Emu
A flightless bird whose father sits on the eggs for eight weeks without eating or drinking.
Frilled Lizard
Australian dragon lizard that flares a bone-and-cartilage neck frill to startle predators, and if the bluff fails, runs off on its hind legs.
Gerenuk
A bipedal antelope of Africa's dry thornbush that rears onto its hind legs to reach leaves other antelope can't, and does not drink standing water, relying instead on the succulent plants it eats.
Greater Jerboa
The desert rodent that flees predators in leaps measured at up to 3 meters long, on hind legs about four times the length of its front ones.
Red Kangaroo
Australia's biggest marsupial, hopping at 64 km/h on powerful hind legs, balanced by a tail it can also rest on.