Nobisaku Nobi

Nobisaku Nobi is Nobita’s ancestor who appeared in the original manga and in an episode from the 1973 anime, 1979 anime and 2005 anime series. Like his descendants, he is not the brightest or most talented individual and is not very skilled at hunting. He wishes to be a samurai like his idol Omaru.
His appearance looks the same way as Nobita Nobi. He always wears glasses in, a jacket with a t-shirt on it, and a farmer's hat. Unlike the 1979 (Remade) and 2005 (Second Remade), he has a ponytail instead without the farmer's hat and doesn't wear glasses.

(Source: Doraemon Wiki)