Novels containing individuals that have an ability/trait to have monsters and other creatures be their allies/pets or novels in which nonhumaniod creatures are smart enough to be considered a separate sapient race and several of which befriend/ally with the protagonist. 
*FYI: The List isn't sorted by any standard other than the order in which they were added.
** Please note that I am only one person, so I may have missed some novels. In such a case, leave a comment, and I will do my best to add it!