I know I'm a little late to the Year of the Snake party, seeing as it began this past Sunday, but I had originally intended for today's post to be ready this past Monday morning. Unfortunately, it took a little longer to dig into the content than I thought it would.
Like the Monster Indexes that have come before this one (including the Lycanthrope Index, Giant Index, and Spider Index), today's PDF (Monster Index: Snakes) gives you OSR stats and information for 40+ snakes, including notes on their poisons, special attacks, etc.
From adder to viper, constrictors and poisonous snakes alike, this PDF has your snakes need covered, from tongue to tail. It includes not only the stock of serpents common to the various early editions, but stats out some that were left incomplete, and adds some completely new ones to the list (like the giant two-headed snake).
Click here for the free MediaFire download of the PDF
Old-school Adventures™ Accessory MX2, Monster Index: Snakes.