The spider robots were robots that X.A.N.A. either made or retrofitted within the Jungle Research Facility. They were X.A.N.A.'s only cybernetic monsters. They were first seen in "Lab Rat," but they were only in their vivarium that time. They later became a real threat in "Bragging Rights," when X.A.N.A. uses an activated Tower to control them to deal with intruders. Ulrich and Yumi had to fight them to destroy the generator.
They were shown to be able to jump very far, walk on walls and ceilings, and stab with their legs. The ones that hadn't been destroyed by Ulrich, Odd, and Yumi were incapacitated when the Jungle Research Facility's generators were destroyed.
In "A Lack of Goodwill", Aelita finds out that the electronic implants manufactured at the New Mexico Research Facility were being made for these, as X.A.N.A. can control specifically made objects in the real world directly with activated Towers.