The Simpsons: 10 Hidden Jokes Everybody Missed
8. Dan Castellaneta's Sneaky Cameo
The Simpsons went all meta in the season 13 episode I Am Furious (Yellow) when Bart created a crude web series based on Homer called Angry Dad and sought out a professional voice actor to provide the character's vocals.
Said voice actor was a character the fans had never seen around Springfield before, a guy referred to only as the star of The Tracey Ullman Show. He also happens to be a dead ringer for Dan Castellaneta, who provides the voice of Homer in real life.
Castellaneta's 'd'ohs' and 'woo-hoos' are instantly recognisable, but the actor himself is not unless you happen to be an avid fan, although a number of viewers may have picked up on it once the character started delivering his uncanny Homer impression.