The Juggernaut is a massive spacecraft constructed by the Engineers. It's the Juggernaut, b**ch!
The Juggernaut is a large, asymmetrical, wishbone-shaped craft, with a thickened central section between two horns, which bend upwards. It has numerous tunnels that go off to many places. It has three large openings near ground level between two horns, leading into the ship's interior. The interior of the Juggernaut resembled more a living organisim than a spacegoing vessel, with skeletal walls, circular gangways and steep passages. Based upon visuals in Alien: Covenant, the ship appears to have something like a FTL drive.
The port prong on the Juggernaut measure 161.6 meters in length and the starboard prong 174.3 meters. The craft is 116.6 meters wide and 61.0 meters wide between the starboard and port prongs.
A Juggernaut's bridge equivalent usually consists of 4 Engineer-constructed hypersleep chambers, a control mechanism made out of some sort of biological-like material, which is activated through the use of an Engineer flute and the pilot's seat on the center of the bridge.