This has bugged me for years, as I could never think of the title and I've never seen it on one of those Looney Tunes collections:
There is an old warner brothers cartoon (my guess is it's from the late 50s or early 60s) when a bulldog or a sheepdog (can't remember) with a strong Brooklyn accent is trying to teach a fox how to become a watchdog. The fox became the protagonist because he told the dog that he wasn't really a fox; he was a dog interested in learning the master's tricks. The dog sees through this, and accordingly runs him through the ringer, concluding each bit with a "lesson," i.e. "that's lesson 2 - never let them..." right after he's dropped an anvil on his head or something like that.
Does anybody know the name of the short that I am talking about?