Downward Dog is one of the most recognized yoga poses out there. You can try to pronounce it in Sanskrit as Adho Mukha Svanasana (Ah-doh MOO-kuh shvan-AHS-uh-nuh)
Downward Facing Dog stretches your hamstrings and your calves muscles. It also strengthens your shoulders and arms creating a strong upper body. Meddy Teddy loves to practice downward dog, it provides him with a nice base. Make sure you get his arms straight and his legs straight as well, trying to make him look like an inverted letter V. To practice this pose you have to engage your hands and your feet.
Keep your fingers wide apart and strong. Try engaging your quads by squeezing them, this will help pull the soles of your feet down to the yoga mat. If your feet don't touch the yoga mat that is ok, it will come with time. To help you remember Downward Facing Dog, think of your face pointing "down" towards the mat. With Upward Facing Dog, your head and gaze shine up towards the sky.
Take a look at Meddy Teddy doing a Downward Dog. This will help you set him up properly.