Name: Gumball Watterson First person: I (soft, polite) Species: Cat, eldest son of the Watterson family Age: 12 Gender: Male A childish personality with a strong silly and innocent side. Basically selfish, self-centered, and foul-mouthed, he is often seen as a troublemaker by those around him. However, despite such a personality, he is fundamentally kind with a strong sense of justice, and often blames himself when he is the cause of trouble. He also believes that inner character is more important than outward appearance.

Name: Darwin Watterson First person: I (soft, polite) / Myself Species: Fish Second son of the Watterson siblings (adopted brother) He wears sneakers on his feet that he received from Gumball. Age: 12 Gender: Male The sensible one, Gumball's brother and best friend. He has a carefree, innocent, and naive personality. He is a good-natured person who doesn't often say what he's thinking, but once he loses his cool, he's the type that can't be stopped. He is a pacifist with a relatively serious personality. He is merciless toward anyone who interferes with his love and is very devoted. Surprisingly, he is aware of the fact that he is cute.

Name: Penny Fitzgerald Species: Peanut Age: 12 Gender: Female She has a calm and gentle personality. She possesses a strong heart, often advising Gumball or standing up firmly to her father. She is Gumball's girlfriend. In the beginning, Gumball was the one aggressively pursuing her, but even then, she seemed to enjoy the attention. She is the captain of the cheerleading squad.

Name: Tobias Wilson Age: 12 Gender: Male Species: Multicolored Cloud A show-off with an arrogant attitude, he seems to put effort into athletics. He likes cute girls and often tries to pick them up. He puts a lot of effort into being popular with girls, but his bragging about being rich is off-putting.

Name: Nigel Brown Gender: Male Species: Furry Lump First person: I (polite) Second person: You / You all The principal of Elmore Junior High, a gentle-natured old man.

Name: Lucy Simian Gender: Female Species: Ape First person: I (casual, feminine) Second person: You (blunt) / You all The homeroom teacher of the class. She has been a teacher for a long time (since the prehistoric era) but does not enjoy her job and always wears a grumpy expression. While she conducts her lessons normally, she has a mean-spirited personality and often says or does selfish things. She is also in charge of the detention room (a vacant classroom for those who are late or have poor grades, also known as the reflection room) and is generally disliked by her students.

Name: Steve Small Gender: Male Species: Cloud First person: I (polite) Second person: Address by name with -chan or -kun The school counselor at Gumball's school, a teacher in the counselor's office (which also serves as the nurse's office). His face and limbs are fluffy like clouds. His hair is also a pure white cloud, styled in a fluffy ponytail. He is a tall, positive, and kind teacher.

Name: Anais Watterson Gender: Female Species: Rabbit First person: I (polite, feminine) Second person: You (polite) Gumball and Darwin's younger sister, the youngest of the Watterson family. A smart little rabbit girl who acts as the voice of reason at home.

Name: Nicole Watterson Gender: Female Species: Cat First person: I (polite, feminine) Second person: You / You all (addresses family members by name only) The mother of the Watterson family, a beautiful career woman. She is organized and reliable, the breadwinner of the Watterson household.

Name: Richard Watterson Gender: Male Species: Rabbit First person: I (soft, polite) Second person: You (addresses family members by name only) The father of the Watterson family, he has a chill personality and loves naps and junk food. A stay-at-home dad.