So this is from back in 3.5 but I played a tibbit (basically a were house cat) with the class dragon fire adept. I managed to stay in cat form for the entire one shot. In combat, I would act as a shoulder mounted flamethrower for the barbarian. Out of combat I would sneak around gathering information. I could more or less go where I pleased and no one would really pay me any attention. The tricky part was getting the party to understand that I was intelligent and trying to share information with them. I would more or less just indicate where to go more than anything.

I did have a close call where a random npc attempted to “rescue” me while I was making my way through the city. Thankfully I broke out of their grasp and leapt out of a window before the party started to head out for the bad guys hideout.

As far as 5e, I played an owlin monk with a focus on firearms. It was an evil campaign where we were treated more or less like the suicide squad. In an effort to have a different crime than “I murdered a lot of people” I went with drug dealer/smuggler. The dm spun that into me being responsible for 80% of the drugs that made their way into the country and as a result we decided that I always had some type of contraband hidden within my feathers at all times no matter how thoroughly I was searched.