This colossal snake is closely related to the Amazonian Boa. This is frightening because it exists today. However Titanonoa died 60-63 Million years ago. The reason I preceded with the picture above is that Titanoboa was a MONSTER that could devour a large human without blinking.
For Americans, that is 50 feet long, 2+ tons, its width larger/higher than your bed or kitchen table. Andableto eat small mammals in a single bound with jaws that open to the size of a doorway in your house.
Still not sure how big it would be, check out these photos from The Smithsonian Exhibit
See the video BELOW