Xenogenesis
"Jodahs, a human-Oankali child who, like all such children, goes into metamorphosis - but for the first time, instead of entering maturity as a hybrid male or female, begins to transform into a member of the third Oankali gender, the gene-manipulating ooloi. This is the final stage of human-Oankali integration: a child of partly human parentage, but with strange alien abilities."--Publisher description.