Mixamo
Adobe's web service creates skeletons for humanoid models and offers previewable, adjustable, downloadable animation clips.
Why use it
Prototypes and small teams gain locomotion and performance motion without a dedicated rigger, then import it into a DCC or engine.
Where it fits
Use art, animation, audio, levels, and narrative to make the game easy to read and its world convincing.
What to check
An Adobe account is required and auto-rigging targets standard humanoids; motion sameness, retargeting, and usage terms need project review.