" By this time, Fast and Sister had both grown larger than I—my body was the same size, but my legs were shorter and stubbier. Hungry was the runt of the litter, of course, and it bothered me that Fast and Sister always abandoned me to play with each other, as if Hungry and I belonged together out of some sort of natural order in the pack. Since Fast and Sister were more interested in each other than the rest of the family, I punished them by depriving them of my company, going off by myself deep into the culvert. I was sniffing at something deliciously dead and rotten one day when right in front of me a tiny animal exploded into the air—a frog! "

― W. Bruce Cameron , A Dog's Purpose Boxed Set