After regaining Vigil's Keep from the Darkspawn there is a kitten located outside the keep in the courtyard.
You can interact with the kitten and choose to pick it up and keep it, if you do so it is added to your inventory as a gift.
When Anders has a high enough approval rating he will tell you of a kitten he used to own, you can gift him the kitten you found for more approval. After doing so the kitten will become a usable item in your inventory, it's use it not yet known.