AutoReivs are machine-based creations used extensively in Ergo Proxy for a variety of tasks. There are several different types.
Companion-type AutoReivs provide, as their name suggests, companionship to their master or masters. Pino is an example of a Companion AutoReiv.
Knight-type AutoReivs are units designed specifically for combat, resembling medieval-like knights. Kazkis had such models in his possession.