Sibling Rivalry

Ok so like alway I had a "study period" at school and I didn't feel like doing any work.
I had asked one of my friends... lets call him Patrisha, to tell me what to draw (something more exciting than a water bottle)and bam he asked for the Nemean lion. Slightly proud at him for realizing I am going though a Greek Mythology faze at the moment I drew him this pathedic excuss of a lion. At first it was just the Nemean lion then I relized hey this could be any old lion. And that is when Cerberus came into the picture literally. So before I drew him I had to think what suited the pic since Nemean was rouring I thought rival, so then I was like "whats the perfect rival for a gigantic lion?... A gigantic three headed dog!" So this for me became the origans of the cat and dog rivalry. And when looking into the family tree Cerberus and the Nemean lion are brothers. So really when cats and dogs fight it could be a old sibling rivalry.