The original idea with the sketch rendering of the boys was meant to be a really crude stick drawing. But then Matt and Trey thought that since the show is already rendered in such a crude fashion, it would be funnier to go the other way and have a detailed drawing of what the boys would look like if they were real people.
The appearance of the bearded park worker that pranks the boys, is based on the appearance of Kyle McCulloch, a member of the writing staff. McCulloch was originally going to voice the character as well, but Parker and Stone were not satisfied with his voice work.
The title is a reference to Free Willy
The whale's name Jambu is a reference to the famous whale Shamu.