Yes a Prius can tow a small teardrop trailer since teardrop trailers don't weight much and in fact I've pulled a teardrop trailer around my town to a camp spot one time with my small lawn tractor so if my lawn tractor can pull the teardrop trailer a Prius car should easily be able to tow the teardrop trailer since they don't weigh all that much.
You just have to add a hitch to the Prius and some trailer wiring for the lights and you should be good to go.
Any small car should be able to easily tow a Teardrop trailer or really small camper trailer.