No you cannot
You collect them from your animals
No, you cannot.
when your animals have little coins above their heads tap those and you will get coins and experience. To get an animal go to "Animals" and you can use your coins to get one.
Once they finish breeding and you place them in your zoo, they start generating coins as well.
Reach level 17 and you can buy the whale for 2,500,000 coins coins
999999999
A Hippo does not cost coins. It costs 68 stars per hippo.
Reach level 24 and buy it for 17,000,000 coins
Tiamat
Reach level 16 and you can buy it for 600,000 coins
If you reach level 6 you can buy it for 8000 coins