Dil tries to prove aliens are real to Tommy, Phil and Chuckie. Even so Tommy tries to out prank him. Angelica schemes to be paired with Sean at the Spring Fling school dance. April Fools' Day has always been a big hit with the 'Rats. Only this year, no one knows who is pranking whom when everyone seems to be collaborating on secret plans to have the greatest prank. Meanwhile, Angelica tries to be a nicer person to get Sean's attention.
This episode's title is a reference to the phrase "tomfoolery".
When Betty has a hot flash and sticks her head in an ice bucket, all the ice cubes fly out and onto the floor. One cube stops falling before it hits the floor.
There's a part when Susie says, "If anyone needs a good deed, it's Ms. Faucet Face." Her mouth wasn't lipping that.
When Didi talks about all the pictures being upside-down except Dil's pictures, one of Dil's baby pictures is upside-down.
When the kids are at the Java Lava, the "camera" is behind Phil and Lil. If you look closely, you can see Lil's outfit change!
In the Java Lava, Tommy says that Dil thought Chuckie was an alien until the Wednesday before. As of then after The Alien, all of the Rugrats mistake Chuckie for an alien at least once.
Ending Tagline: "Hah?" "Heh?" "Huh?" - Angelica, Ms. O'Keats, and Mr. Pangborn, respectively.
Kimi didn't appear in this episode for some unknown reason.