The duck tank is a new activity that was released for ToonFest 2017. It is a booth that contains cutouts of hills and a large notable seltzer bottle beside it with a chair inside. It is named the "duck tank" due to the Toon inside being dunked is Cleff, who runs the Notations Office Supplies building in Minnie's Melodyland. This is the first cooperative activity released to ToonFest, as multiple Toons need to work together to dunk Cleff.
Inside the tank, Cleff is seen sitting on a chair above some water. The target for the duck tank is not activated by going up to it. To activate the target, Toons must hit the Cog dummies around the ToonFest grounds enough times until a message pops up indicating the activation of the target. The Toons then have to hit the booth's target enough times for it to go down. After enough hits, Cleff will be dropped down into the water, and everyone who helped to dunk Cleff is rewarded with ToonFest tokens, the amount depending on the amount of time taken to dunk Cleff into the water.
- The duck tank was first found in the files for ToonFest 2015 without textures. It was later teased in various screenshots for ToonFest 2016, but was never released due to the various delays of the event.
- The duck tank contained numerous bugs when it was first released. When the target became present, it would cause great amounts of lag to occur to the point where a player's screen would freeze numerous times. The target was reported to move very fast as well.
- The target also had a bug where it would not go down even if hundreds of pies were thrown at it, but would sometimes go down if only one pie was thrown at it.
- Toons who didn't participate in helping to dunk Cleff were also given ToonFest tokens when he was dunked.
- The duck tank was the only one of the three activities that were planned for ToonFest 2017 that was revealed, the other two being the trivia mini-game with a quizmaster and the ToonFest ToonTasks.