Gray Voice (often shorted to Gray) is one of the few Chozo remaining during Samus' time. Like all other Chozo, he has only appeared in the Metroid manga. When the Chozo infused Samus with Chozo genes, they used DNA samples from Gray Voice, giving them a unique biological relationship, similar to a father and daughter, that allows Samus to hear his thoughts on at least one occasion.
Relative to his counterpart Old Bird, Gray Voice seems to be more pragmatic in personality, initially contesting the Chozo's adoption of Samus and even siding with Mother Brain and the Space Pirates when the latter successfully invade Zebes. The apparently betrayal turned out to be a ruse after all, however, and it is later revealed that Gray Voice intended to destroy Mother Brain when her ambition made itself apparent. Gray Voice equips a Chozo Power Suit to himself and attacks Mother Brain, but Ridley intervenes and strikes a fatal blow before he can bring Mother offline. Before Ridley can finish him, Gray launches an attack skyward that allows the fleeing Chozo to escape a Space Pirate attack.
- "Gray..." —Metroid (manga), Samus Aran, Vol 1 Ch 2 Pg(s) 10
- "In order for you to inherit Chozo genes, we used his DNA... In other words, even though you are two different species, you two are very similar to father and daughter. You could very well have a unique connection." —Metroid (manga), Platinum Chest, Vol 2 Ch 12 Pg(s) 4
- "Old Bird!! What do you plan to do by bringing a human child here." —Metroid (manga), Gray Voice, Vol 1 Ch 2 Pg(s) 2
- "Gray... Voice... Why are you with the Space Pirates..." —Metroid (manga), Samus Aran, Vol 1 Ch 7 Pg(s) 2
- "Gray planned to destroy Mother from the start... is that right?!" —Metroid (manga), Samus Aran, Vol 2 Ch 12 Pg(s) 2
- "...An attack from below...?!" —Metroid (manga), Samus Aran, Vol 2 Ch 12 Pg(s) 16