Nathan is very reluctant, depressed, and lazy as he hardly moves from his chair and is constantly seen reading newspapers, watching TV, drinking cans of soda, or eating. Because of this, he is usually nicknamed "Mr. Lump" by Mrs. Beady.
Nathan believes that his wife is crazy because of her constant assertions that the animals are sentient, which he is tired of. He considers her a "nut job" and sometimes wishes that he was dead. Once, in the video game, Nathan has stated that he knew he should have married Nora's sister instead. However, it has actually been shown that despite this, he still loves and cares about her.
He has a severe dislike for his nephew Snotty Boy due to his mean personality towards him. Snotty Boy usually destroys his uncle's possessions, frustrating Nathan. In "A Tale of Two Snottys," when Pig lived with the Beadys disguised as Snotty Boy, Nathan actually preferred Pig as his nephew rather than the real Snotty Boy after Pig started being nice to him and comforting him. At the end of the episode, when Pig's cover is blown and Mrs. Beady literally throws him out, Nathan was devastated that his real nephew was back to his normal self.