Reminds me of the SpongeBob episode with Wormy turning into a butterfly and somehow scaring SpongeBob and Patrick until they and the rest of the Bikini Bottom-ites destroy their own city out of irrational fear. I think that terrifying live-action close-up was actually a horsefly instead of a butterfly, from what I've been told.
But anyway, that "scary close-up" joke still has me in stitches to this day, and this variation with Charlie cracks me up, this type of visual gag will never get old for me.