The Rubber Duck is a small, yellow, plastic duck. It has orange eyes and it has "PATЯICK" written below its wing, with the "R" written backwards. This shows that the rubber duck obviously belongs to Patrick.
In "Stuck in the Wringer," Patrick is looking for his rubber duck, which SpongeBob ends up slipping on. The episode also includes Patrick's name written on the rubber duck.
In "Naughty Nautical Neighbors," Patrick is shown in the bathtub with a duck and a toy boat.
Another rubber duck appears in "The Paper," however it is Squidward's.
In "Squid's Day Off," Squidward mentions a rubber duck that Mr. Krabs wants him to get, possibly as a joke.
A rubber duck also appears in "Suction Cup Symphony," being squeezed by Patrick, when he is interrupting Squidward conduct the symphony.
Another rubber duck appears in the episode "Safe Deposit Krabs," where it is included in Patrick's Bank Breaking Kit.
In Battle for Bikini Bottom, on some occasions, if one defeats a robot, a rubber duck may pop out of the exploding robots.