This shader is available in the Unity Asset Store. (Link)
The shader dissolves any given Object like in Borderlands the enemies are dissolving through acid and fire.
The package comes with two shaders:
The Shader Dissolve_TexturCoords uses the TextureCoordinates of the given Object. That gives you the Opportunity to set where the object should Dissolve first.
The Shader Dissolve_World Coords uses World/Object Coordinates to Dissolve the Object. This method gets rid of the Texture seams, but is not suitable for animated Objects.
Amount – Animate this to Dissolve the Object
StartAmount – Sets the Value from witch the dissolve starts
Illuminate – Sets the Value of Illumination for the rims
Tile – Sets the tiling of DissolveSrc and DissolveSrcBump
DissColor – Sets the Color for the rims
ColorAnimate – Sets witch RGB-Value should be animated X = Red, Y = Yellow, Z = Green (Ignore W)