Theraphosid

Pseudotheraposa gigaphopysis, also known as Theraphosids or Giant Spiders, are a genetically engineered creature that resemble monstrously large pinkfoot goliath bird-eating spiders. They were created and originally manufactured at ExtraGen, until the eventual collapse of the corporation, leading to their transport and continued housing at The Menagerie.

Creation
Theraphosids were among the first creatures created by ExtraGen as part of their 'Nature Improved' line. The base is a Theraphosa apophysis (The Pinkfoot Goliath Bird-Eating Spider), which was heavily modified, with the intention of using them on an industrial scale. As well as the 100 fold increase in size, they were engineered to produce thick silk fibers, for use in many products. To withstand their increased size, they grow a rudimentary pseudo-endoskeleton, which allows an increased number and size of tracheae, allowing a sustainable amount of oxygen transfusion, meaning they can breathe while in regular oxygen, though are somewhat more sluggish. To get around this, the containment chambers they are housed in are pumped full of air that has a higher oxygen content.

They were housed at ExtraGen for many years, but during a major disaster at ExtraGen, a number of Theraphosids escaped, and several workers were killed by them. During the cleanup of ExtraGen, the remaining Theraphosids were captured and brought back to The Menagerie.

The Menagerie
The Theraphosids continue to be used for silk production in the lower levels of The Menagerie. Like most of the carnivorous creatures at the Menagerie, they are fed synthetic meat.