The Horde Dreadnought is a vehicle from the 1985 animated series She-Ra: Princess of Power.
She-Ra: Princess of Power
The Horde Dreadnought is a massive seafaring vessel built by the Evil Horde. It had a dangerous Plasma Cannon as its main defensive weapon.
Upon arriving at the Isle, the Dreadnought was too large to get close enough to deposit Hordak and his troops on land, so the vessel was anchored and a small Horde Hovercraft was used to travel to the Isle itself.
She-Ra caused the Dreadnought to flip upside down by removing the top of a mountain and throwing it into the ocean, causing a tidal wave that overturned the Horde Dreadnought.
Admiral Scurvy also commanded a Horde Dreadnought, though it is not made clear if his ship is the same one from the earlier episode or a different one.