Roboform Christmas tree

The Roboform Christmas Trees were used by the Roboform to wreak havoc on Earth during the two invasions that took place on Christmas.

These remote-controlled trees could spin at extremely high speeds and rip apart everything in their path. One of them used this ability to nearly destroy Jackie's flat. Another feature the trees had was to send out remote-controlled bombs disguised as baubles. (DW: The Christmas Invasion, The Runaway Bride) These baubles were used by the Doctor to decimate the Empress of the Racnoss and her children.

Like many other robots, they can be stopped using a sonic screwdriver. (DW: The Runaway Bride)