The Army Painter Green Stuff
From the manufacturer:
The original Kneadatite (best known as Green Stuff) is used by model makers and hobbyists for conversions, filling mold lines and sculpting miniatures.
- GREAT FOR ADDING BITS OR HIDING MOLD LINES
- HARDENS WHEN THE TWO COMPONENTS ARE MIXED
- USE WITH SUPER GLUE TO GLUE LARGER COMPONENTS