Always an amusing situation.
There have been many animals, fiddles, cellos, horns etc have AAdvantage miles who travel on their own purchased seat. Of course, it is against the AAdvantage rules and usually the miles are forfeited, or transferred to the owner as a one time exception.
One of the most popoular and frequent travelers in F was Nipper, the RCA dog. They say he would walk in, take his seat and not move until he deplaned at his next promotional stop. His mileage was in the six figures.