Johansson accepted the role because she liked cartoons and was a fan of "The Ren & Stimpy Show". When Jeffrey Tambor signed for his voice cameo, he saw his character (King Neptune) and joked, "This is me." He remembered the first cartoon he saw, "Bambi" (1942): "My first cartoon, I had to be carried out crying It was "Bambi". It's like the great American wound: the death of Bambi's mother. 'Run, Bambi, run!'" Another guest voice was Alec Baldwin; Stephen Hillenburg said that the actor recorded his character Dennis on a "phone": "I wouldn't say that about his performance. He might be mad if we said that. Technically, it was like he was in another booth in the studio."