I have found that a used box is about the best toy you can offer a foster kitten. Sarge likes to just lay in the box, jump all over it swatting at things, and if I add a little kitten ball toy, it can keep him busy for a long time.
Here Sarge is scoping out a "new" box that was shipped to him special (ha-ha) and my tiny 5 pound dog, Button, is checking out what all the fuss is about. These two have been best buddies since the beginning. Button like to lick messy milk off faces, wrestle, and have a good time with Sarge. All done gently, like the cute little dog that Button is. As Sarge has grown, it has turned the tables, and Button has to be much more careful to not get beat up by the kitten!