kleptomania; kleptomaniac
A psychological condition characterized by a recurrent urge to steal, typically without economic motive. Can refer to the disorder itself or a person with the condition.
Kleptomania is considered a type of mental disorder.
彼は窃盗狂で、必要のないものまで盗んでしまう。
He is a kleptomaniac and ends up stealing even things he doesn't need.