The great thing about the Unity Animation System is that you can animate nearly any property of the UI. To create an Animation Clip, simply open the Animation Window (Window | Animation or Ctrl + 6), and with the UI element you want to animate, select Create:
Once you do so, you'll be prompted to save the Animation Clip.
After creating the Animation Clip, you can then add any property to the clip's timeline by clicking on Add Property:
Doing so will bring up every component of the object, as well as a list of all of its children: ...
