Ever since art was created following in the wake of the October 2013 trailer, DeviantArt has been a place for some of the artists to upload their art in a shared Filly place.
Created by Fillyfan on the 26th of October 2013, and is estimated to have 34 pictures as of the 8th of September 2014. The largest contributors are Phyrokyro and HareTrinity, with 9 and 8 pictures respectively.
Most of HereticalRants' Filly pics in the group was lost when he announced on his DeviantArt account that he'd delete his entire art folder. Two of them has been re-added later on, but with moustaches added to them.
In November 2013, the group attracted the attention of Mosuga, who stated herself as the co-creator of Filly. She seemed surprised that it had attracted a fandom.
Xeregon, who later rose to prominence on FiMFiction and Fillychan under different names, was first discovered when he uploaded long text analyzements of the October 2013 and April 2014 trailers to DeviantArt.
Isles of Funtasia
Created by Phyrokyro on the 9th of August 2014, he created it under the assumption that Fillyfan was no longer active and that the FillyFuntasia group was dead. This was proven wrong by Fillyfan the following day, which left Isles of Funtasia without a clear purpose.
It currently has 29 pictures, a few of them by Phyrokyro. It has a chat group, which requires a DeviantArt account to get in.