Does a module *require* a mod.mymod.php file?

I have an idea for a module (I think it should be a module) that will allow the easy uploading of many images.

So all the functionality would be in the CP-side of things. There would be a few settings, then mostly a “GO” button to do the upload.

So, does a module HAVE TO have a mod.mymod.php file or can I just have an mcp.mymod.php?

Thanks