The harmonious tribe
There is a hidden tribe of changelings living amongst the ponies of Equestria.
Their true nature hidden from their neighbours as well as themselves.
These hidden changelings can be Equestria's greatest champions and her greatest enemies.
To better understand the benefits and dangers the harmonious tribe represents, we must examine what drives them. The primary drive of a harmonious changeling is the same as that of any kind of living being: the drive for sustenance. The primary food source for any changeling is: love, affection, respect,kindness, happiness, joy,friendship, in other words harmony. A changeling can not generate harmony on it's own, but skilled masters of harmony have learned to draw sustance from the even the most unlikely sources.
Changelings tend to be specialised in how the draw in their sustance, specializing in how they stimulate nearby sources of harmony to share in their wealth. This might cause some minor social problems for those changeling as their emotions will reflect the food they consume. This can be easily compensated by socializing with other changelings with different feeding habits. For a harmonious minded changeling there is no difference between socializing and feeding especially with other changelings. A succesfull changeling is a like a richly filled banquet for other changelings.