Here is the full list of all 31 My Coloring Book: Animals achievements. It takes around 0-1 hour to unlock all of the achievements on Windows.
Color the Unicorn according to example.
Color the Goat according to example.
Color the Big Lion according to example.
Color the Hippo according to example.
Color the Fish according to example.
Color the Fox according to example.
Color the Squirrel according to example.
Color the Deer according to example.
Color the Raccoon according to example.
Color the Chick according to example.
Color the Ram according to example.
Color the Dog according to example.
Color the Cow according to example.
Color the Puppy according to example.
Color the Rabbit according to example.
Color the Pig according to example.
Color the Pony according to example.
Color the Bear according to example.
Color the Hare according to example.
Color the Tiger according to example.
Color the Owl according to example.
Color the Small Lion according to example.
Color the Ostrich according to example.
Color the Elephant according to example.
Color the Zebra according to example.
Color the Chameleon according to example.
Color the Parrot according to example.
Color the Crocodile according to example.
Color the Turtle according to example.
Color the Armadillo according to example.
Color the Giraffe according to example.