What is the worst behaved thing your pet has ever done?

My cat who is 3 years old this month jumped on the kitchen table when he was 2 and knocked over and broke a family heirloom. A 70 year old crystal fruit bowl that my grandparents got handed down to them at their wedding went shattering to the floor. My mom still doesn't like my cat but I still love him to death. I can't help it. Animals are alive and what he broke was a material object...it's still sad, but I'm just sayin' :)