The History of Comedy This new episode of the documentary series explores the difficulties that comedians face involving mental illness and substance abuse. 7 and 10 p.m. CNN
The Big Bang Theory Leonard and Penny (Johnny Galecki, Kaley Cuoco) offer Sheldon’s (Jim Parsons) old room to Raj (Kunal Nayyar) after he moves out of his apartment. 8 p.m. CBS
Supernatural Sam and Dean (Jared Padalecki, Jensen Ackles) fight a transparent deadly hellhound in this new episode. 8 p.m. KTLA
Grey's Anatomy A power struggle within the hospital staff gets in the way of treating a trauma patient. Ellen...