"Monkey Rat" is slang for Opossum. To those who have never gotten up close and personal with an opossum, this slang term may seem silly. However, as more and more South American spieces are available through pet stores, more and more people are familiar with the monkey-like hands and feet, and the prehensile (grabbing) tail of Opossums.
I have a pet monkey rat, and she is the snuggliest of all my pets. And she climbs like crazy!
A racial slur for all races using the term "monkey".
"That group of people over there is a much of rat monkeys"