Okay, I know Take-sensei isn't looking to be scientifically accurate, but NO, Green Anacondas don't grow to 10m, nor do they eat humans.
People like to claim they've seen Anacondas up to 40 feet long, but the longest verified specimen was 5.21m (17' 1"). Oftentimes, reports of massive Anacondas come from untrained laypeople who are just kind of guessing.
On top of that, they're extremely shy creatures, and keep to themselves. The reason one of them would attack a human is if the human encroached too deep into it's territory, they've gotten to close to the nest, or the snake recently shed and is vulnerable. No matter the reason, it's only in self defense, and meant to scare away threats. In general, humans are too big for Anacondas to eat, and they wouldn't really taste good if they tried.