I think J
agar has one of those crazy German umlat things on it which I can never find the correct shortcut for on the keyboard, so the English butchering of it is Jaegar, like G
oring/Goering and Schr
oder/Schroeder. Generally I think you add an e after the letter with the umlat if you want to butcher it, or if your keyboard is too english.
Mind you, this is from an Englisher that regularly made a German cry at his abortive forays into the German language.