cunning old man; sly old fox
Derogatory term for an old man who is crafty, shrewd, and not to be trusted, likening him to a tanuki (raccoon dog) known in folklore for trickery.
あの狸爺には気をつけろ。何を企んでいるかわからない。
Watch out for that cunning old man. You never know what he's plotting.
村の狸爺がまた誰かを騙したらしい。
It seems the sly old fox of the village has tricked someone again.