In the game production side, we share a link to the Adobe Mixamo site that is already used a lot. When you enter, 121 3D characters and 2484 character motions are uploaded, and you can download them in a 3D format called (Autodesk) FBX. This format can be read in 3ds or Maya, and can be used in Unity or Unreal Engine. Character motion has been made a lot for very special cases. (Basic motions such as walking, running, sitting, etc., as well as getting up zombies, walking with wounds, jab flying, push-ups, etc.)
Regarding AI, there have been quite a few studies recently that extract poses or facial expressions from images and then retarget them to 3D characters, and I share this as a good dataset that can be used in these studies. I think these studies can be used for avatar animation, and conversely, it can be used for recognizing meaning from motion (what motion?).