Chuck Norris is so immortal, even he killed Death.
Chuck Norris vs. Death
Explanation
Explain Bear
Listen up, you knucklehead! You really think you're smart enough to understand this joke? Let me break it down for ya. Chuck Norris is so tough that he's basically unkillable, right? So the joke is that he's so immortal that he even managed to kill Death itself. Get it now, Einstein?