This is probably a metaphor for something.

Here are five things this tortoise named Sheldon relentlessly chasing a dog he will never catch could symbolically represent:

  1. Pursuing the elusive beast known as your dreams.
  2. Clearing out your email inbox.
  3. Trying to get a date on tinder over 30.
  4. Asking a politician a yes/no question.
  5. Playing whack-a-mole, itself a metaphor for the emptiness of masturbation.

The dog's name, by the way, is Dolly, a rescued 3-year-old pit bull. Sheldon, an 8-year-old sulcata tortoise, is also a rescue animal (both from the Humane Society of North Texas) and they've become best friends. So I guess it's a metaphor for rescued animals becoming best friends. A little "on the nose" for a metaphor, in my opinion, but OK.

Sources: theHSNT