Here is the full list of all 29 Watch Your Plastic Duck achievements.
Collect 50 ducks
I want to believe
Thaw out a prehistoric duck
Call the priest!
Mass extinction
Get a duck with all stats from 20
Click various objects 5000 times
Get a glitchy duck
Get duck level 20
Especiallly dragon fire
Get a duck with any stat equal to 20
Get a duck with all stats from 10
Watch ducks for 5 hours straight
Get a duck that drowns 10 ducks
Get a duck that drowns 5 ducks
Get duck level 10
Collect 25 ducks
Get a duck that drowned 1 duck
Get a duck with any stat equal to 10
Witness the rainbow duck
Get duck level 5
Collect 5 ducks
And the sky is gray
Click various objects 500 times
Touch the pumpkin
Touch the gift
Click various objects 50 times
Use easel and change duck
Click various objects 5 times