I'm not going to post video much, because video tends to use a lot of bandwidth and storage, and Tumblr is not known for its healthy financial position.
We are now in the position where a determined artist (someone who could actually do character sheets or key frames) could, in theory, use AI to animate an entire low-budget, sometimes wonky-looking, animated series about a clique of Tumblr users. (On the other hand, at least for Grok, it's not based on keyframes yet—which is, in some ways, not surprising.)
We are also in a position where every Internet meme could potentially be animated. Very cyberpunk. But does it really add much, or is it just noise?
As with AI image generation before, what you can do with depends on whether you're flowing with or against the currents of the training data. And also as with AI image generation before, there's an implicit, gambling-like element—each image rendering takes a little bit of time, and you don't know if you'll like the result, or if it will just be bad.
Thus, as with AI image generation before, a lot of it is a matter of iteratively generating and pruning, sometimes in a frustrating way, when you and the AI are not in sync and thus the AI doesn't understand you, or when what you want is too improbable in the AI's training data.