Joe Pesci:
Tommy DeVito (Goodfellas): Tommy has some great anger issues that can help with his prowess and will power, not to mention he can use a gun and knows how to kill people.
Harry Lyme the Burglar (Home Alone 1 and 2): Harry, on top of his burglary skills and sneakiness, has the most incredible luck and durability I've seen in most any movie character. It'd take a lot to kill this guy. Unless, of course, you're a 10 year old kid.
Leo Getz (Lethal Weapon series): Leo is a talkative douchebag who annoys people with his never ending rabble. Combine that with his penchant for amatuer detective work, and you get an annoying dick.
The result:
A short, annoying snoop with serious anger issues who knows how to kill you and will not die.