If you are referring to Anacondas, I was gonna post this huge post earlier today but decided against it. But seeing as it popped up anyway I'll just say a few things.

Lets just go by the trailer shall we. They are saying 50 Feet Long 450lbs *i think* and traveling at 150 ft per second... And its not even a single Anaconda, its an orgy of them. Are you kidding me? This just seems silly to me now that I am so interested in snakes. I couldn't care less before, but now it bothers me. To me it seems like they are trying to potray big snakes as huge killing machines. When is the last time you saw a 50 foot anaconda, let alone a group of them? You never did, cause they don't exist. And if they do, nobody has ever seen them. 99% of all the worlds giant animals have been discovered by experts estimates. The chances of finding another one after all this time of looking is slim. o_O The longest snake ever recorded was just over 40' and that was a retic if I'm not mistaken. And Black Mamba's are the fastest snakes, at least on land. It seems to me like they just balled all these snakes together and turned it into a movie.