Dream symbolism

What does it mean when your dream apparently uses one friend as a symbol for another?

mobbsy told me I'd do this, and who am I to disappoint?

[Poll #229421]

By assumption the change would be a perfect physical change, rather than current-day surgery, and would affect genetically determined facts about the person, not acquired ones; i.e. nature is changed, not nurture. Whether the change would be temporary or not is up to you. You may list yourself if you want and (only) if you do you can list an extra person.

Leave reasoning (if you have any l-) in a comment.