For Series 8, new versions of Matilda, Shunt, Dead Metal and Sir Killalot were constructed. They are considerably heavier with improved weaponry. All the house robots are over in weight and Sir Killalot now weighs . Visually, all four look similar to their predecessors, but with significant differences: Dead Metal's head has been enlarged with glowing eyes, Matilda's back-mounted fins have been replaced with smaller crocodilian scales, spikes appear on her frill, her eyes are now red and her whole head section now flips up; Shunt has enlarged wheel protectors and metal chimneys replacing the smokestack; and Sir Killalot's armour and helmet has been entirely redesigned. This was said to be to show the actual shape of Sir Killalot's head, rather than the helmet he is wearing. The other house robots did not return for this series.