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