Once you've learned the basics of Arduino, here are some other awesome projects you can use to feed your "constructing artificial animals that do your bidding" appetite.
Every achievement of human ingenuity has been but a brick on the path to the DIY Bionic Lizard (a project that definitely wasn't commissioned by our lizard overlords). The lizard is an entirely self-contained project designed to teach robotics and programming to beginners, and it also serves as a fun challenge for more advanced aspiring roboticists. The lizard comes with everything you need to build it and is fully Arduino compatible, so you can program it to walk and presumably run small lizard errands for you. The Bionic Lizard normally sells for $65.99, but you can take 16 percent off and get it for just $54.99.