| | | Part 1 |
| Roosevelt | Walsh-Adams | Claude's brother. Aka: Roo. |
| Ben | Walsh-Adams | Roo's brother. |
| Rigel | Walsh-Adams | Claude's brother. Orion's twin. |
| Orion | Walsh-Adams | Rigel's twin. Claude's brother. |
| Claude | Walsh-Adams | Rosie and Penn's gay son. |
| Penn | Adams | The Adams's father. |
| Rosalind | Walsh-Adams | Penn's wife. The Adams's mother. Aka: Rosie. |
| Heather | | Rosie's neighbor. |
| Jupiter | | The Adams's puppy. |
| Poppy | | Rosie's little sister. |
| Taya | | Claude's friend. |
| Pia | | Claude's friend. |
| Annlee | | Claude's friend. |
| Ms. | Danielle | Claude's teacher. |
| Ms. | Terese | Claude's teacher. |
| Carmelo | Walsh | Rosie's mother. |
| Rebecca | Appleton | A kindergarten teacher. |
| Dwight | Harmon | The school principal. |
| Mr. | Tongo | The hospital's handyman. |
| Frieda | | Rigel and Orion's friend. |
| Victoria | Revels | A district representative. |
| Grumwald | | A fictional character in Claude's story. |
| Princess | Stephanie | A fictional character in Claude's story. |
| Davis | | One of Claude's classmates. |
| Susan | | One of Claude's classmates. |
| Carrie | | One of Claude's classmates. |
| Marybeth | | One of Claude's classmates. |
| Jason | | One of Claude's classmates. |
| Lloyd | | Grumwald's study partner. |
| Nick | Calcutti Sr. | Nicky's father. Cindy's ex-husband. |
| Cindy | Calcutti | Nicky's mother. |
| Nicky | Calcutti | Claude's friend. |
| Anna | Gravitz | A nurse. |
| Jane | Doe | A transgender. |
| Chad | Perry | The man Jane met. |
| | | Part 2 |
| Aggie | | Claude's friend. |
| Natalie | | Claude's friend. |
| Kim | | Claude's secret Santa and friend. |
| Alice | | Claude's bear. |
| Miss | Marple | Claude's sheep. |
| Oscar | | The boy Aggie likes. |
| Mattie | | The boy Mattie and Kim likes. |
| Chester | | The new boy from Claude's neighborhood. |
| Marginny | Granderson | Rosie's new friend. Aggie's mother. |
| Frank | Granderson | Marginny's husband. |
| Cayenne | Granderson | Aggie's sister. |
| Roverella | | The Granderson's chihuahua. |
| Mr. | Menendez | Claude's principal. |
| Mrs. | Wonks | Rosie's patient. |
| Howie | | Rosie's co-physician. |
| James | | Rosie's co-physician. |
| Yvonne | | The owner of Rosie's clinic. |
| Derek | McGuinness | Roo's enemy. |
| Mrs. | Birkus | Roo's teacher. |
| Harry | Eliott | One of the Adams's neighbors. |
| Mark | | Harry's iguana. |
| Mr. | Mohan | One of Claude's teachers. |
| Marnie | Alison | One of Claude's schoolmates. |
| Keith | Rice | Aggie's friend. |
| Josh | Edison | Claude's math classmate. |
| | | Part 3 |
| Ling | | Claude's guide. |
| Sorry | Ralph | K's ambulance. |
| Mrs. | K | Rosie's colleague in Thailand. Aka: Kathoey. |
| Mya | | One of Claude's students. |
| Zeya | | One of Claude's students. |
| Dao | | One of Claude's students. |
| Naw | Ga | The school principal/teacher and mayor. |
| Steph | | One of Claude's friends. |
| Nok | | Claude's tour guide. |