Luigi's Flat Joke

I'd tell a Luigi joke, but it would fall flat faster than the line on his victim's heart monitor.

Luigi
Line
Death
Heart
Victim
Health

Explanation

Explain Bear

Alright, listen up, you knucklehead. The joke is saying that a Luigi joke would be really bad, so bad that it would "fall flat." But it also compares this to a heart monitor flatlining, meaning someone died. Get it? It's funny because death isn't.