Bandraginus V

Bandraginus V was a Vegan shipyard (PROSE: First Frontier) with a billion inhabitants, the Fourth Doctor calling it "a planet of a thousand million souls".

Around 1878, Zanak materialised around Bandraginus V and destroyed it, (PROSE: First Frontier) mining it for all its mineral wealth, including Oolion, an element only found on Bandraginus V and Qualactin. Following this, the Captain super-compressed it and added Bandraginus V to his collection. The remains of this planet were dropped into Zanak's core and expanded to fill in the space.

Some Oolion stones were scattered around Zanak as a result. (TV: The Pirate Planet)

Behind the scenes
The name "Bantraginus V" is likely a reference to "", the home for one of the key ingredients in in Douglas Adams's The Hitchhiker's Guide to the Galaxy. The Pirate Planet was Douglas Adams' first contribution to Doctor Who.

Given that Xanxia stated she "[had] ransacked planets from Bandraginus to Calufrax", it is likely this meant Bandraginus V was the first planet to be the victim of Zanak's mining operations. (TV: The Pirate Planet)