Standing all of 2 feet, 7 inches tall and tipping the scales at 50 pounds, Sebastian was didn't look much of a threat, but to ignore his presence would be foolish.  He wasn't well armed, just a couple daggers, nor was he well armored, just hardened leather, but that didn't mean he couldn't hit you, or that he was easy to hit.  Small target, quick movements, and handy with things that required a delicate touch.  That was what he was good at.  While he might have to reach up a bit to get to your pockets, you might want to make sure you guard your purses.