This happened to my friends and myself not too long ago during a game of Dungeons and Dragons we were all playing. We were using Version 3.5 rules, and I was playing as an Elven Druid. My character was also in the company of a Human Sorcerer and a Human Bard/Barbarian cross-class.

It is important to note that we have a house rule when it comes to Knowledge Checks: rolling a D20 to determine how much one knows of a particular subject. In our group, such rolls are made "blind" behind the dungeon master's partition so that only he, and not even the roller, knows just how good he rolled. We find that this makes for better role playing.

Now on to the actual story:

We were deep into the underground lair of an evil cult that has captured one of our comrades, walking down a long and twisting corridor. So far we had managed the journey with little incident, but adventurers never have such luck for long.

Up ahead we could hear the echoing of a loud hiss. We decided to continue forward cautiously, in case of ambush. Further ahead, we discovered a tattered and torn piece of snake skin. This, of course, meant that it was my job to identify what species of snake it belonged to, and to judge if it were a threat or not.

I rolled my Knowledge (Nature) and, unknown to me or the other players, managed to get a natural one. Our lovely dungeon master informed us that I believed the snake skin in fact belonged to a huge anaconda. With this information we readied our weapons. If we were going to rescue our friend we were going to have to make it by this snake! Our Sorcerer cast a fireball spell and tossed it as far as he could in the direction of the hissing. And huge explosion erupted and we walked into the dust. When the debris cleared, we found the charred bodies of a group of garden snakes. And to make matters worse, the explosion had given out position away to the enemy.

I rolled my Knowledge (Nature) and, unknown to my comrades or myself, got an exceptionally low score. But I was able to "identify" the skin as belonging to a snake no bigger than a few feet. Our fears set aside for the moment, we continued down the hallway with little worry. We would later learn to always worry. We turned a corner and came face to scaly face with a pair of huge pythons. The pair were, of course, parents to a brood of young which they were willing to die protecting. The little darlings couldn’t have been more than just a few feet long.