Detail this asset from Unity Store: Original Link
This is a paid asset, but now you can download Animation Converter Free.
Animation Converter v1.02p03
Convert animation clips to a different animation type:
⭐ Humanoid ⇆ Generic ⇆ Legacy
Convert between all 3 animation types in every possible combination.
⭐ Convert Unity Animation Clips (*.anim)
Natively Unity can only convert animations when importing them from a 3D modeling format (*.fbx, *.blend,…).
⭐ Motion Capture to Generic/Legacy
Convert (free) motion captured animations to make them useable for your Generic/Legacy characters.
⭐ Reuse Animations
Convert Generic/Legacy animations created for one character to a Generic/Legacy animation useable by a different character.
⭐ *.anim to Humanoid
Convert animations created using Unity’s Animation Window to Humanoid.
⭐ Extensible
Comes with an easy to use C# API and with the full source code of the editor window.
⭐ Detailed Manual
Detailed HTML based manual in a similar style as the official Unity® manual.