In Yiddish, he would be called a Goniff...

goniff - n. - (Yiddish) a thief or dishonest person or scoundrel (often used as a general term of abuse).

We are usually pretty careful about not both leaving the dining room table at the same time if there is food still there - especially protein. But Asher was giving us a hard time during dinner last night, and so we were both a little frustrated, and we both left the table, and there were still one and half chicken breasts (boneless) on the table. The little goniff took the whole one and left us the half - and ran up under his bed and scarfed that piece of chicken down in record time. And held it down too!