I was fired for destruction of property and gross misconduct can I fight it?

I work at a movie theater and we have coloring books for kids from the movie 'Shaun the sheep.' While in box office , with nothing else to do I colored in one of the sheep as a drag queen and wrote above the sheep "Shaun the Transgender sheep." I'm gay so I have no problem using term. A couple days later that same coloring book was given to a five year old girl. The mother came into my work angry and was threatening to post a picture of what I had written on social media , after she had calmed down she told my manager that she wasn't personally offended about what was written and changed her mind about posting it online. I went into work the next day and was fired for destruction of property and gross misconduct. Yes those coloring books are property of the movie theater but everyone colors in them. I did not intentionally mean for the coloring book to be given out.