Changelings

In General
Ever since their appearance in the season finale, a great deal of fan art and fiction has surfaced pertaining almost exclusivley to the changelings and their leader, Queen Chrysalis.

A widely accepted theme within the changeling fandom include the fact that the race works with a "hive-like manner". The drones, or workers of the hive, are under the leadership of a queen. This is however, based on the evidence shown within the show itself. Mainly being the fact that the changeling's appearance and behavior is already reminiscnet of typical insect societies we see today.

Like Discord and Nightmare Moon, changelings have been expressed in a positive light by many artists and writers.

In Fan Fiction
Though most fan fiction pertaining to changelings is unique on its own, there has been a sort of pattern within all these fan fics that is accepted due to the setting the characters are in. (Please note that the following is mostly based on speculation of mutliple stories) It begins with a changeling, who after being blasted away by the force field created by Shining Armor andPrincess Cadance, lands somewhere within Ponyville and surrouding countryside. Sometimes the changeling is injured, or in some weakened state. When the changeling finally realzies what is happening, they will not initialy go back to the swarm. This is either through losing contact with the swarm, thorugh choice, or through some other inability preventing them from re-grouping. The changeling may end up disguising his or herself as they search for the nourishment of love, which will leade to the events of the story.

Some fan fic examples of "changelings in Equestria" include Smoke and Mirrors and A Changeling to Remember. Interesting enough, it appears that both stories occur within the same universe, simply being told through different perspectives of multiple changelings.

In Fan Art
From comics, to vectors, and to painted masterpieces, changelings have been expressed visually through art. Some have used this art to develop their own OC's while others have used it to express their thoughts on the new villains. Still others use the shape-shifting abilities of the changelings for humorous purposes, such as having an annoying character copied a hundred-fold for example.

Changeling (Other Caste?)
Briefly seen in the show itself, what appears to be an armored changeling is briefly seen before the main characters charge to battle. Many speculate he or she is some sort of leadership caste, perhaps a captain, general, or commander. This idea of an "officer" in the changeling ranks has led to fan fictions, and artists recreating the changeling in various stances.

Sites that you should check out:
deviantART

fimfiction.net