A sentient ink splotch that emerges from Peter's sketchbook, Inkling can transform into various shapes and writes to communicate. He enjoys drawing and helping Ethan, Peter, and Sarah while developing his sense of self.

Ethan and Sarah's father and the creator of a popular comic book series, he is depicted as a bearded, graying man. Peter struggles with depression and writer's block following his wife's death.

A nine-year-old girl with Down syndrome and Ethan's sister, she is cheerful with strong opinions, enjoying repetitive activities. Her journey involves embracing new experiences that break her usual routines.

A talented artist and Ethan's school rival, she has a complex relationship with him due to her admiration for his father and jealousy of Ethan's bond with him. Her actions reflect her desire to help her own family.

The owner of Prometheus Comix and Vika's father, Karl serves as both a publisher and antagonist. He's faced with financial troubles and is driven by his interests in profits over artists' welfare.

A key antagonist who contrasts sharply with Inkling, Blotter is a piece of Inkling that has gone rogue. His violent and unpredictable nature results from absorbing low-quality comics.

Ethan's best friend and supportive ally, Soren is characterized by his constant startled appearance due to reading scary comics. His role highlights the importance of friendship and support.