Your description makes it sound almost like a tick. If it is round in shape,that's probably what it is.The rubbery body is so it can expand,while gorging on your pet's blood. Be sure to check your pet's WHOLE body,to make sure there are none embedded in it's skin.A bad infestation of ticks,left unattended to,can lead to anemia,and other problems for your pet.Don't pull them out,for they can lose their heads under your pet's skin,and cause infections.Go to your local pet store,or even your vet,and get some good fllea and tick shampoo.That should get rid of them.Hope this helps,and good luck!