The Metal Spiders were used by Lady Cassandra in both The End of the World and New Earth.
The Metal Spiders are small robots with four tentacle-like appendages and two saucer-shaped body parts. The top part had a red eye which could emit light. Individual, they aren't very strong or dangerous, but can be formidable in large groups. The Metal Spiders were transported by metallic orbs, which were in turn transported by the Adherents of the Repeated Meme.
In The End of the World, Lady Cassandra used them to try to destroy Platform One, since they could easily sneak around the satellite, damaging important systems. In New Earth, she used to them spy around New Earth.
