American Dad! S12 E03 Scents and Sensei-bility

"From the creator of "Family Guy" comes a man who will stop at nothing to protect his country."

Steve and Snot are fed up with being bullied. When they enroll in a karate class, Snot is brainwashed by the sensei, and it's Steve's mission to get him back. Meanwhile, Klaus develops a horrible odor and is forced to be an outside pet.