So here is something interesting:
SillyPutty
Then this got me thinking
Video
By mixing Iron oxide (Fe2O3) with silly putty we have a magnetically manipulative material, that can also be easily molded.
So what if we also mix the correct percentage of aluminum powder into the silly putty+Iron oxide mix?
We should have a moldable mixture of thermite that is magnetically changeable, all we need now is a fuse and we potentially have a very interesting material.