PARIS — Imagine looking out the window one morning and seeing a gigantic spider perched on the roof of a neighboring building — its eight legs extending to the street below.

Then you walk downtown and realize that a 50-foot-tall creature with the head of a bull and the body of a man was looming above you.

Hallucinating? Not in Toulouse, France, where the city has given itself over to an immersive form of street theater, bringing to life creatures like the giant spider and the Minotaur, the mythical monster from Greek mythology that is half bull and half man and said to have lived in the center of a maze on the island of Crete.

Both creatures are the conception of François Delarozière, the artistic director and leading creative force behind La Machine, a theater company that works with technicians and designers to fabricate mechanical creatures on a vast scale and creates public spectacles around them.