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