UPDATE:

been to vets, its not a tick, but hes not sure what it is.....
he said it could be from an injury, or just growing tissue, and hes not concerned as its not bothering Diesel in the slightest, he then said, if it gets any bigger, or Diesel is biting at it or scratting, to take him straight back and they will wip it off....apparently a lot of animals get random lumps and its just excess tissue


worry over!