Experiment 18 in the Sonic GeneX series. Sonata the Unicorn, or "Sonny", is a gentle soul with a soothing, feminine voice. His songs are the only thing that can calm Experiment 17, Bolt the Creature, when he's upset.

Sonny is also an empath. His unicorn horn enables him to sense the emotions of those around him.

He is a pacifist and tends to need Bolt to defend him in dangerous situations.