The House of Kaa, by Richard B. Sale (epub/Kindle/pdf)
Scotland Yard thought it strange that the firm of Gorgan & Wilkins imported only regal pythons. But no law was being broken. And they thought it very strange when the Cobra, a lone avenger from India, suddenly appeared in London. But the Cobra had once helped them, so there was no investigation. And the greatest surprise of all was the appearance of Deen Bradley of the British Intelligence—who had an amazing plan to offer.