Left: WT (Glaze); CT (Carrot Top) Bottom: Pip (TheDumplingz); ? (It actually has just a question mark) Top: BJ; BP. Not sure who either of these are. BlackJack and Brown Pony come to mind, but I doubt it's either of them. Right: GM (General Mumble); PC (Pinkie Cake? Not sure)
Glaze, TheDumplingz, and Mumble are all British (unless I'm very much mistaken), so that could be a deliberate theme.