They have called it the Spiderweb Galaxy because of its incredible appetite for other clusters of stars.
It was found in photos taken with the Hubble space telescope, such as that here, and is so far away that we are seeing it as it was early on the universe, just two billion years after the Big Bang.
Dozens of smaller galaxies can be seen merging with the monster Spiderweb, which lies 10.6 billion light-years away from Earth. They are being sucked in like flies at speeds of several hundred miles an hour from distances of more than a hundred thousand light-years away.
Dutch astronomer George Miley, from Leiden Observatory, discovered the Spiderweb with colleague Roderik Overzier in the constellation of Hydra, the water snake. Dr Miley said: “The new Hubble image is the best demonstration so far that large massive galaxies are built up by merging smaller ones.”