Fat rat is probably the phrase you are looking for. A rat is a rodent, and fat means overweight.
Plump Ump.
Bleak peak is a hink-pink or rhyming word pair answer to the riddle "dreary mountaintop."
A rhyming word pair for an unhealthy sea mammal is a pale whale or frail whale
not a bent cent
shy fly
fat rat
fat rat
Rhyming word pair for home for a rodent?
fat rat
Rhyming word pair for happy boy?
Fat Rat.
pink mink
fat rat
pink mink
fat rat
Plump Ump.
plump ump