When you take a yoga class (especially Ashtanga, Vinyasa, and Jivamukti classes), sometimes the instructor will call out the names of the poses in their original language, Sanskrit. Here's a list of some animals in Sanskrit and the poses they're named after. Knowing these Sanskrit words really helped me to remember the names of certain yoga poses.

Baka - crow, crane or wading bird, as in Bakasana (Crow pose)
Bheka - frog, as in Bhekasana (Frog pose)
Bhujanga - snake or serpent, as in Bhujangasana (Cobra pose)
Gomukha - face resembling a cow, as in Gomukhasana (Cow Face pose)
Kapota - dove or pigeon, as in Salamba Kapotasana (Supported Pigeon pose)
Kukkuta - rooster or cock, as in Kukkutasana (Cock pose)
Kurma - tortoise, as in Kurmasana
Matsya - fish, as in Matsyasana (Fish pose)
Mayura - peacock, as in Pincha Mayurasana (Feathered Peacock pose, also called Forearm Stand)
Nakra - crocodile, as in Nakrasana (Crocodile pose)
Svana - dog, as in Adho Mukkha Svanasana (Downward Facing Dog pose)
Simha lion, as in Simhasana (Lion pose)
Vatayana - horse, as in Vatayanasana (Horse pose)
Vrschika - scorpion, as in Vrschikasana (Scorpion pose)

Humans were not the first to do yoga. Way back in India, animals were observed in nature, and noted for their particular abilities and accomplishments. To imitate these qualities was considered a high sign of spiritual enlightenment, that's why so many yoga poses are named after animals. Check out this post to see animals doing yoga.