- Ivan Dragnic: A 15-year-old boy from Canada, who is sent to live with his Aunt Kate in the Amazon rainforest after his parents pass away in a car crash.
- Kate Cold: A herpetologist and conservationist, as well as Ivan's aunt, who lives and works in the Amazon.
- Celia Castro: A healer from the Caboclo people, who becomes a close friend to Ivan and teaches him about the rainforest and its magical creatures.
- Juma
- Ojos de Oro (Golden Eyes): A mystical jaguar with golden eyes that Ivan believes is his spirit animal.
- The Beast: An unknown creature that destroys entire villages and kills any who cross its path.