So tried Sculptris and came out with this after about 30 mins

Artwork Works in Progress
1

Slapped it right into blender and tinkered with some materials
Went right into unity3d from to.

rock.png960×540 245 KB

Screen Shot 2016-07-22 at 10.02.38 PM.png683×529 85 KB

Screen Shot 2016-07-22 at 10.03.00 PM.png685×556 57.5 KB