The Milgians are a race of large sentient bipeds who are described as looking as though they were made from building blocks. They hail from a world that has apparently suffered severe environmental damage, and thus they travel in living starships that they communicate with telepathically; the link is forged by sharing their genetic material with the ships.
They first made contact with the Federation sometime around 2368, when one of their starships, the Zar, was deliberately sabotaged by its chief engineer, Veleck, who had been bribed by the paranoid Orianian leader General Basha to create a situation that would draw the USS Enterprise away from Oriana while its captain, Jean-Luc Picard, was busy attempting to negotiate an end to that planet's civil war. Veleck's treachery was discovered by the Enterprise's engineer, Geordi La Forge, and he was subsequently relieved of his post.
Later, after Basha was removed from power, his wife and successor, General Talanne, announced her intention to open diplomatic relations with the Milgians to collaborate on environmental repair efforts. (TNG novel: Nightshade)