Unicron's size is never specified in any canon materials, aside from the vague term "planet size". In "The Transformers: The Movie", Unicron's height appears to be anywhere from several kilometers (as when handling Galvatron) to several hundred kilometers (as when attacking and destroying Lithone and Cybertron's moons, and attacking Cybertron). A planet-mode diameter of has been suggested and robot-mode dimensions can follow from that estimate, provided that there is no change in size (compression or expansion) common among so many Transformers. One scene in the movie shows Jazz driving out of one of Unicron's eyes, just small enough to fit through them, though in another scene the Quintesson ship Hot Rod arrived in is tiny compared with the eye. Unicron is also small enough to stand on Cybertron's surface. In season 3, it is shown that the eyes from Metroplex and Trypticon (both city-sized Transformers) are the perfect size to use as replacement parts when Unicron orders the ghost of Starscream to steal them. However, later in the episode when Trypticon moves Unicron's head, the head is larger than Trypticon's entire body. (Note: However, the eyes could be only small components for his Optic Sensors to be reformed and/ or completed.) In the storyline "The Ultimate Doom", Cybertron appears to be smaller than Earth's own moon (and by extension, this would indicate Lithone would be too small to be a planet), making Unicron's dimensions in the cartoon harder to define.