Coco came to Cesar "Dog Whisperer" Millan biting and challenging all people and other animals. During Coco's successful rehabilitation, Cesar's youngest son Calvin fell in love with the little guy, and Coco ended up a permanent part of Millan pack.

Coco went from demon dog known as "four pounds of pure aggression" to one of the best behaved dogs imaginable, a trusted member of the Millan family, and a helper for the famed Dog Whisperer in calming down other troublesome dogs that come to Cesar to salvage.

In the top photo Coco is on the right. On the left is the notorious Sammy, formerly known as El Diablo, whom Coco helped rehabilitate by being a great role model.