This is the largest rat I've ever seen in my entire life.
, London resident
“They’re increasingly being kept as pets because they tame quite nicely,” she said. “It’s extremely unlikely this was not someone’s pet,” she added.

A Gambian pouched rat found in Florida FWS and Wildlife Services
Guinness World Records doesn’t have a record for the world’s longest rat.
The largest species of rat, however, is the slender-tailed cloud rat found on Luzon in the Philippines.

Jaroslav Vogeltanz via Creative Commons
The tree-climbing rodent can get to be as large as 3.3 feet in length.