Ray Tsing Tao was one of the child survivors of the first Federation expedition to Triacus, a planet in or near the Epsilon Indi system, in 2268. Oddly unfazed by the induced suicide that claimed their parents – the adults in the party – Ray and the other survivors were actually the puppets of a non-corporeal entity who haunted the planet following the extermination of his race.
Ray shared his manipulator's opinion of the dead world, saying once finally off it, "what's so good about that place?"
The ghost, whom the children called "the Friendly Angel", delegated some of his power to induce delusion and crippling anxiety in adults. Planning to spread his baneful influence, he had the children use these powers to seize the USS Enterprise and take her to a populous world outside her assigned patrol area. The ghost was foiled when James T. Kirk helped Ray and the other survivors recognize their sense of loss and sadness. (TOS: "And the Children Shall Lead")