As you can see here, I was successful in creating a copper layer using some obscure shape as the source image. Pragmatically speaking, the design is simple, but it could easily be more complex.
Here is the original image:
I created the image arbitrarily in MS Paint, and saved it as a Monochrome BMP image. This is important, make sure it is Monochrome (ie two colors only).
Then I opened up my library in which I would like to create the part with the obscure contact point. Create a brand new "Package" and then run "import-bmp.ulp". It is a sort of macro that comes with EAGLE. To run it, simply type "run", and you'll be brought to the directory of ulp's. Find the import bmp one and follow the procedure.
Only select the black color when moving through the wizard.
While following the procedure, you'll be presented with an option to set which layer you want the image to be imported as. You can make it one of the copper layers here, or perhaps a silkscreen layer or whatever else.
From there, you could set a pad in the center of the image so that you can have a pad to wire to in your board layout. EAGLE will not recognize your image as a pad so that's why you add the additional pad in a clever place where it will not screw up your design, but so EAGLE knows what pin/pad whatever, that your schematic needs to connect to.
Best of luck.