No animal exists as half squirrel and half rabbit. A rabbit is a lagomorph and a squirrel is a rodent. Rabbits and squirrels do not belong to the same species, therefore they cannot interbreed, explains University of California at Berkeley Evolution 101.
Although a rabbit and a squirrel have a distant common ancestor, these animals can be differentiated by the way their teeth are arranged. A rabbit has two pairs of incisors, with the upper incisor before the lower in the jawbone. A squirrel has large incisors and cheek teeth separated by a large gap.
Squirrels and rabbits also have different diets. Squirrels are very nearly omnivorous and can eat meat if they must. A rabbit eats grass, weeds and garden vegetables.