In my community travels, I have found that literally none have heard of La Corua or its legend.
At the Tucson's Birthplace Breakfast, I ran into an old acquaintance, Jesús Garcia; Sonoran native and naturalist at the Sonoran Desert Museum. We discussed the future of the Mission Garden and I gave him my card. He knows of La Corua well, and told me that it indeed is a real snake - not just a mythical animal as I understood it to be. I was thrilled and told him how much keeping Sonoran folk heritage alive means to me.
So, here is the biology I uncovered about my business' namesake:
The boa constrictor (Boa constrictor) is found from South America to central Sonora. In Sonora, the Mexican boa constrictor or corúa (B. c. imperator) can be a rich dark reddish color in tropical deciduous forest or a paler grayish color in coastal thornscrub. Corúa (also coruba) is a pre-Columbian name. They are often found in canyons and are thought to be guardians of the aguajes (water holes). Unlike other serpents, killing them is thought to be bad luck (the water will dry up).