Husnock warship

From Memory Alpha, the free Star Trek reference

Husnock warships were large starships operated by the Husnock prior to 2366. This type of vessel was much larger than a Galaxy-class starship, capable of being seen from the surface while in orbit, and capable of destroying all life on a planet.

In 2366, a Husnock warship attacked and destroyed a Federation colony on Delta Rana IV. Unknown to the Husnock, an energy lifeform known as a Douwd was also living on the planet in the form of Kevin Uxbridge. In retaliation for the Husnock attack, the Douwd used its enormous powers to completely destroy the entire Husnock race. (TNG: "The Survivors")

Following the Husnock attack, the USS Enterprise-D arrived to investigate finding all life destroyed except for a small patch of grass and a house within which lived the Douwd and his wife (who was really an illusion).

As the Enterprise crew grew more suspicious of Kevin, his wife, and the means by which they had survived, the Douwd recreated a Husnock warship to drive the Enterprise away.

The recreated warship was a Husnock vessel, according to notes in the script, but whether or not the recreation was as or more powerful than the original remains unknown.