In this task, you're given a story (which contains five sentences only). Your task is to find all the characters which are available in the given story.
Q: Sentence1: I was playing with my dog in the backyard. Sentence2: Suddenly, he bit my shorts. Sentence3: The shorts were ripped through the pocket! Sentence4: I had to throw the shorts away. Sentence5: I learned to be more careful when playing with my dog.
A:
I (myself), Dog