Sewer gators (alligator mississippiensis darwinii) and giant rats (rattus rex) are said to live in USA's largest sewer system, New York's sewers. Without people, will these elusive cryptids survive?
Life After People
1 Day after people
Giant rats and sewer gators are doing well for one day after people, at least for now.
2 Years after people
The New York's sewer system is falling apart, so the giant rats and sewer gators will have to move out or die.
200 Years after people
New York's sewer system is now gone forever, but not its former inhabitants. Giant rats now thrive in former streets of New York (without humans killing rats, rats grow to about the size of a small bloodhound). Sewer gators are also fairing well, unlike southern alligators (which are being outcompeted by pythons, and couldn't tolerate the cold), former sewer gators can tolerate cold and snowy environments very well and there are no pythons in its reign, so former sewer gators, now called Northern alligators (alligator canadanis), are thriving in human-less cities, towns, urban areas, suburbs, ponds, lakes, and rivers of North America.
2,000 Years after people
Giant rats and Northern alligators have spread out to parts of Southern Canada, Western USA areas (including California, Oregon, Montana, etc.), and Eastern USA areas (including Florida, where Northern alligators are fighting against pythons to reduce competition on Florida alligators and pythons, so because of this, Florida alligators are now safe from invasive pythons for the next 3 million years).