During the last decades of the Republic, the Jedi order had replaced any need for a unified military for protection. Instead, private interests maintained their own armed forces in local territories, and the engines of commerce could afford the most powerful and most effective armies. Despite legislation designed to curb the potency of any one private army, the massive corporations were able to build sizable droid forces. The dwarf spider droids favored by the Commerce Guild appeared in the Separatist ranks. The four-legged dome-shaped mechanical arachnid featured a powerful, centrally mounted laser cannon.
from – Dwarf Spider Droid | StarWars.com
