This is a paid asset, but now you can download Skinned Metaball Builder Free.
Detail this asset from Unity Store: Original Link
Skinned Metaball Builder v1.12.1 (Latest version)
Create organic meshes with metaballs in editor and runtime.
Optionally, the mesh can be skinned automatically so that it can be deformed by animation or physics simulation.
Created mesh can be saved as an asset for general use.
Fully implemented with Unity C# script.
– customizable
– no dependency on platforms
What’s new
ver 1.121 released(2020/12/10)
-Added a sample material with vertex color
ver 1.12 released(2020/12/09)
-Vertex color supported (with blending between nodes)
But not for “IncrementalModeling” mode yet.
ver 1.10 released(2015/09/17)
-new feature “IncrementalModeling” mode
-introduction -> (http://nkdtr.hatenablog.com/entry/2015/09/19/231458)
-“Place Metaball” shortcut changed to “Shift+Ctrl(Command)+E”
(it was “Shift+Ctrl(Command)+C” before, being the same as “Open console”)