YouTube Create integrates three basic free animation tools into YouTube, using your existing account…
* GoAnimate is like a very basic CrazyTalk Animator, with some branded theme-packs and characters (none of which are currently available on the YouTube version). You can also record voice from the microphone, and import your own images (if you pay to upgrade to a ‘premium’ account). The best of the bunch, I’d say. Although for a mere $38, CrazyTalk Animator completely outclasses it and (once you consider all the apparently complex and fiddly ways GoAnimate entices you to spend money) is much better value.
* Xtranormal has what looks like 3D CG, although in a limited range of themes. There appears to be no way to actually see your rendered movie before you post it to YouTube (although you can preview it as a storyboard with sound). Audio appears to be limited to text-to-speech?
* The rather stupidly named Stupeflix is capped at 60 seconds in length, and is more of an animated greetings card / Powerpoint thing. Ugh.
Servers on these services may be slow, since about 50 millions kids are no doubt visiting right now.