Q: 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.
Sentence1: Casey thought that her toddler had been unusually quiet. Sentence2: She went to check on him and found him with a tub of formula. Sentence3: The powder was all over the place including in his hair and clothes. Sentence4: She didn't know what to do, she felt like screaming at the huge mess. Sentence5: Finally she calmed down and began cleaning the mess up.
A:
Casey, Toddler