Rogue Apprentice

You've spent a bit of time with a variety of people of, let's say, a less than reputable demeanor. In this time you've picked up a thing or two of use but aren't the highly skilled thief or assassin your mentors are.

You gain proficiency in thieves tools, one Dex skill available to the rogue class and gain the sneak attack feature. Your sneak attack is the same as the rogue's but your dice are d4's and you have a number of them equal to your proficiency bonus.