Right now, I'm reading the Japanese translation of Catcher in the Rye.
This sentence has been puzzling me:
奴さん、ジャガーをもってやがんだよ。
I know that the author is saying that his brother owns a Jaguar, but I'm not sure what 「やがんだ」 means exactly.
So my question is: How is やがんだ used and when is it used?