Categorically, the green big anaconda is the largest and most dangerous species out of all anacondas. However anacondas don't hunt down humans and will rarely try to kill them. However this snake is extremely strong and if it did coil, there would be little chance you could escape.
The yellow anaconda is smaller than the green anaconda but is dangerous in the sense that a lot of owners say it is unpredictable and aggressive. And although it is smaller than green anacondas if you let an adult coil around you it could kill you.
The dark spotted anacondas are bigger than the yellow anaconda, but smaller than green anacondas, however they are not very dangerous as they are usually shy and are rarely sighted in the wild.
The Bolivian anaconda is about 4 meters long on average and definitely has enough crushing power to kill an adult human, but like other anacondas it would not go after you.
Anacondas are big enough to kill you but this is greatly exaggerated online. It could be up to this big.
