Roboform Christmas tree
From Tardis Wiki, the free Doctor Who reference
The Robotic Christmas Trees were used by the Robot Santas to wreak havoc among Earth during the two invasions. These remote-controlled trees can spin at high speeds and rip apart everything in their path or send bombs disguised as baubles flying everywhere. (DW: The Christmas Invasion, The Runaway Bride) These baubles were used by the Doctor to decimate the The Empress of the Racnoss.