A Medusan ambassador whose appearance drives humanoids mad, and who joined minds with Spock to guide the Enterprise home from beyond the galaxy.
Kollos is the Medusan ambassador to the Federation, a being of great intellect whose form is so alien that seeing it drives humanoids insane. He travels aboard the Enterprise in a protective container, accompanied by his aide Miranda Jones.
When the Enterprise is stranded outside the galaxy, Spock melds with Kollos so that the Medusan's skill at navigation can bring the ship back. Briefly sharing one body, they enjoy each other's company before Kollos returns to his container.