Muggles' Guide to Harry Potter/Magic/Mobilicorpus

Overview
Mobilicorpus is a spell that allows an unconscious (or perhaps dead) body to be moved.

Extended Description
The Mobilicorpus spell is used in Harry Potter and the Prisoner of Azkaban to bring the unconscious body of Snape along the tunnel from the Shrieking Shack to the Whomping Willow.

Analysis
Professor Lupin used this spell rather than waking Snape because it was simpler, perhaps, than having to deal with him bound up. This spell seems to be related to the Locomotor spell, which is used for inanimate objects, and the Levicorpus spell which appears to lift a conscious body up by the ankles. Additionally, the Latin root "mobili" means "mobile" and "corpus" means "body." This implies the spell is used to move people or other bodies.