Some kind of dromaeosaur and his possum.

Edit: I might as well expound and say this is from an idea I've had for years about a dinosaur-themed children's book or children's book series for both children or adults. In this book or chapter a young dromaeosaur (I haven't decided what exact species and may not ever) gets his first pet and learns a few lessons on how to think about and treat animals ethically.