Darwin is an orange fish. He wears green shoes. As he is a fish, he does not wear any other clothes. As shown (particularly in The DVD), he is quite chubby particularly at his cheeks, which keeps him from suffering pain from objects that hit him. In contrast he has long thin legs that enable him to run very quickly.
Darwin is upbeat and more responsible than his owner Gumball. His special talents include speaking Cantonese, and perfectly impersonating movie legends like Don Lafointe. He has screwd knowledge of the the world around him, and sometimes fails to understand things like numbers, spelling, and the difference between DVDs and kitchen appliences. In moments when he does not know what to do, Darwin will make his infamous c-shaped mouth. In The Pressure, he fell in love with Masami and it is possible that they are now in a relationship. Darwin falls in love with anything wearing a pretty dress, as shown in The Dress. It's alluded to that he might think with his stomach a bit. In The Responsible he was easily distracted by the fish flakes floating about and began eating them, showing that he still has some of his fish insticnts left. And in The Pressure, he claimed to run away forever but just hid in the cafeteria under the lunchline, possibly meaning that he loves to eat food.
- In The Ghost, Darwin says he is a "paci-fish," meaning he is non-violent. But in The Painting, he violently destroyed an "inobition."
- Darwin was the first character to break the fourth wall.
- Unlike most fish, Darwin has no gills. The reason why this is so is unknown, but he probably adapted to breathing on land when he transformed.
- In The Dress, we find that Darwin is left-handed or rather "left-finned" when he's drawing the sexy picture of Gumball in the dress.
- This could be a reference to a scene in Billy Madison where Billy was drawing a similar picture of his teacher.
- Darwin has several profiles on Facebook. He goes by Moby Dick Watterson on one.
Darwin used to be the family pet until he sprouted legs and became one of the Wattersons. He's innocent, naive, and Gumball's best friend.
It was announced that Warner Bros. Pictures, Legendary Pictures and Animal Logic is planning a feature-length film based on the character, entitled The Amazing World Of Darwin. The movie is currently set to be released in theaters on June 11th, 2032. No writers and/or director has been confirmed as of yet but sadly the movie is canceled.