This huge LEGO spaceship is called The Needle and it's built using the Futuron color scheme. The builder Lasse D says it's roughly ten base plates in length which would make it about 8 feet in length I think. So... big.
It's also a very distinctive design with the curving side wings contrasting with the more utilitarian giant thrusters on the back. There's even an Iron Throne on the bridge. Why? No idea, but it looks cool
Check out the Eurobricks forum post for lots more images of the build.