For this achievement you have to first unlock the Duck object for the Laboratory in the main menu. To unlock the Duck, you'll need to beat the Nursery level, Dionaea, with at least a silver medal.
For this particular level, you seem to unlock the medals by completing the level quickly. I got silver with a time of 1 minute, 39 seconds with minimal liquid.
Once you've unlocked the Duck, back out to the main menu and select 'Laboratory'. Hit
for 'Mode' and find the Duck under the objects list. Place the Duck anywhere but the ground level using
or
. Press
to Simulate and you've got the achievement!