Querkus

Querkus was the home planet of a race of giant moving trees that was invaded by the Daleks.

History
Humans planned to colonize Querkus, but they abandoned it after finding out that its forests could kill. Centuries afterwards, the Second Dalek Empire invaded Querkus, for with its vast resources and its strategic position, it would have been the perfect base to establish a new front in the war against Humanity. A Dalek scout craft was sent and at first encountered no trouble, but within moments they were attacked by the Death trees. The Daleks' blasters were nearly useless against them. The Death trees used their incredible strength to rip open the Dalek scouts and crush the Kaled mutants inside. This attack enraged the Dalek Supreme, who sent a battle cruiser which wiped out all life on the world with cobalt bombs. It was only weeks until millions of Daleks came flying out of the production factories. (DWBIT: #47)