Hello Slowly Team, it would be amazing creating a set of stamps regarding the most influential animals in History! Some of them could be:

1) Dolly: the world's first cloned sheep in 1996

2) Laika: the first dog sent into space in 1957

3) Koko: the gorilla that learnt sign language in order to communicate

4) Balto: the dog that saved the town of Nome in Alaska from diphtheria in 1925

5) Cher Ami: the bravest carrier pigeon during World War I

6) Ham the Chimp: the first monkey in space in 1961

7) Mrs. Chippy: the cat that took part in the Imperial Trans-Antarctic Expedition of 1914–1917

8) Alex the Parrot: the smartest parrot that inspired psychological studies over animals' intelligence