The Rubber Duck was first seen on Mission 4 in the Invention Cabinet, however it wasn't used on this particular mission. It appeared again in Mission 9, supposedly as an emergency invention. In Mission 9, you find that it's burst, but players use gum to fix the hole in it and pump air into it. It then sails off to sea from the Iceberg with a tracking device on it. In Club Penguin: Elite Penguin Force Mission 13, Rookie is seen squeezing it hoping something would happen because he had no idea what it was for.
- Rookie doesn't know what it does.
- It appears in the Fall Fair game Puffle Soaker.
- It appeared during the Festival of Flight 2009, as a cloud made by the Cloud Maker 3000.
- It appears in Mission 11 inside the toolbox in the Gift Shop Owner's room.
- In the mission An Agent's Work Is Never Done of the video game Club Penguin: Elite Penguin Force, Rookie tries to stop the Ultimate Proto-Bot 10000 with it.