Choraii

Choraii are a race of cosmozoan entities, living starships that need base minerals as replacement for their organs. They resemble big balls adjusted to each other in various forms, the inner side is full with a liquid, which is breathable to humans. They constantly sing a song which resembles music made by a choir of angels. Hearing this song makes humans adjust to them psychically, to the point that one who lives inside a ball of Choraii usually commits suicide after separation. Choraii view humanoids as animals, and they used to tame some of them. (TNG novel: The Children of Hamlin)