Which of the following have you seen/read/heard?
The Web Planet (First Doctor TV series from 1965)
Doctor Who and the Zarbi (novel by Bill Strutton, based on the TV series)
the 1966 Doctor Who annual (included in PDF format as an extra on the Dalek Invasion of Earth DVD)
Twilight of the Gods (Missing Adventures novel by Christopher Bulis)
Return to the Web Planet (Big Finish audio play by Daniel O'Mahony)