I made a little tool to create fgd entries (HL1 Engine based games only!). You simply specify the type of entity, an entity suffix, the "real name" etc. The fgd entity code will be automatically created. From there you can save it as a new fgd, or copy the code into one of your existing fgd files, as long as the real entity game code exists! (hl.dll)
Screenshot:Download!
Its not really done yet, and only has support for monster_ and weapon_ entities, and im not even sure if a new monster_ entity will work, can't test it here.
Anyway, i hope you like it.
If you find any errors or bugs, let me know.
This program requires .NET Framework 1.1.