IC1101 Beefcake galaxy. The largest we've found.
Just how large is it? Prepare to have your mind blown, because this galaxy has a diameter of 6-million light-years and a mass of about 100-trillion stars. It is nearly 50x the size of our very own Milky Way galaxy and 2000x as massive. If our galaxy were to be replaced with this super-giant, it would swallow up both Magellanic clouds, the Andromeda galaxy, the Triangulum galaxy, and almost all the space in between. That is simply staggering.
http://www.fromquarkstoquasars.com/i...xy-ever-found/