I could make a character who is a humanoid that perfected herself and detached herself from her own mortality in such a way to become immune to many effects that work on others, gaining eternal youth and the ability to be restored by arcane magic at the price that since she detached herself from her mortality, healing spells only worked half as well. Also, she doesn't heal naturally but can meditate on the way the universe was crafted, using the craft skill, to recover. It would be mechanically identical to Warforged but have different cosmetics and flavour. One would be much more like a robot than the other.
In other words--of course an analogy to robots depends on cosmetics!