They are shields. Most have high and in some cases very high damage reduction in exchange they have no real attacks other than a basic shield bash (punch) and no real protection from elements since they are basically metal shields things like fire will melt them and so on.
Against things that do physical damage they are excelent targets while you make an escape or whatever. Wanted to let them do something like half the damage you took went to them... but it was going to be too system stressy to do code wise. So we never did it.
They are still cool though.