Andrey Burgorski, twin to Anatoli, is a sizable man at six feet, with dark hair over pale skin. Full features give him an expressive face. His twin, Anatoli, is also in the human-hybrid project. Andrey has a birthmark that visually individualizes him from his twin: a small mole by his left eye.

Andrey is combined with mockingbird DNA, enabling him to imitate voices and other sounds with near-pitch-perfect accuracy. He uses this skill to communicate clandestinely with his twin, who shares the same skill.

Andrey is the more introspective of the two brothers. He often says, "Let me think about that," when asked for his thoughts on a matter. 

Andrey calls his brother by the diminutive Anati, pronounced "An-a-tee."

We first meet Andrey in Book 6 of The Human-Hybrid Project, Taking the Tower.