I think I read this book sometime in the early to mid 00's, but I have no idea how old it was at the time.
From what I remember, the main character (male I think) finds himself in a fantasy world where he is able to telepathically communicate with some (maybe all?) animals. Most particularly, he befriends a small snake which refers to itself as Me and has the ability to spit highly corrosive poison or acid (I'm pretty sure it literally melts flesh.) The snake is highly enthusiastic and constantly asking "Want Me spit?" and the main character has to spend a lot of time explaining that no, not everything is a suitable target for face-melting poison spray, just a few specific things.
I believe the main character starts the book in our world, and is transported to the fantasy world in the middle of some kind of snowstorm. I think he also returns to our world at the end, with little or no time having passed.
Other random details that I think I remember:
- There's some kind of war going on in the fantasy world. I think one side might be known as "The Federation," but I'm not sure about that.
- I seem to recall Me being referred to as a "wyvern."
- There's a horse or horse-like creature with whom the main character communicates telepathically at some point.
- At one point, the main character has become separated from Me and is looking for him. He asks Me telepathically where he is, and Me says he's "on a tree," which turns out to be not a tree at all but rather the arm of a dead person that Me killed. Me thought it was a green tree because the dead person was wearing green clothing.
I don't remember much of the plot otherwise, and any or all of these details might be completely wrong. Just throwing things at the wall in the hope that something might stick.
I did run across Pip & Flinx while searching, but it's not what I'm looking for. The telepathic snake I'm thinking about was definitely named Me. I don't think it could fly, either.