Eisenkot

Yiddish for iron - eisen  and a distorted form of kop (head), i.e. Ironhead. 

Perhaps the name originator was not deemed especially astute.

Eiger

From the town of Eger in Bohemia.
A famous bearer of this last name was Rabbi Akiva Eiger, or Akiva Güns, Yiddish: עקיבא אייגער, (Eisenstadt, 1761 – Poznań, 1837), an outstanding Talmudic scholar, influential halakhic decisor and foremost leader of European Jewry during the early 19th century.

Eichler

German for oak tree