Danny loved animals, especially dogs. There were times where he desperately wanted to adopt a dog, so then he'd have something he could look forward to when he went home everyday. But because of his job, there were boundaries. He might get called out and not come home for days, neglect would definitely be a major concern for a pet. Needless to say dogs, who need walks in the park, refills on their meals, and an owner they could be loyal to. As much as Danny loved dogs, he wasn't fit to have one.
He found a little black kitten hiding in the corners of his recent victims apartment along with it's new born siblings. When it looked up innocently at Danny with the same green eyes Mac has, Danny couldn't help but to bring him home.