This episode, along with the accompanying episode Deja Vu, is shown rather sporadically. At one point, it was hardly shown at all except on April 1.
The April Fool apparently likes spearmint gum and people can bribe him with it since Timmy did that to convince the April Fool to help him with getting back at people.
The April Fool is shown to be a stand-up comedian, though no one, except for Cosmo, likes his jokes.
This is the first time Timmy saves the world.
This episode aired on October 11, even though it mostly takes place on April 1.
On a YouTube compilation (Aprils Fool's Day Compilation!), there's an easter egg called 'Textless Materials'. This shows textless title cards, the textless intro, the silent, textless end part of the intro, and of course, the textless ending credits. This was shown after the credits of 'Truth or Cosmoquenses/Beach Bummed!'.
The groundhog attacking Timmy every time it sees its own shadow.
People throwing a pie at Timmy at the start of the episode.
Wanda: Cosmo thinks everything is funny. Watch. [floats over to Cosmo] Pudding.
Cosmo: [laughs uncontrollably while holding the April Fool by the shirt] She said pud- and then -ding! [smacks the April Fool and laughing continues]
April Fool: And that Jorgen von Strangle! Have you seen that guy's forehead? They should call it a five-head [Holds up hand, then poofs another finger on to his hand. Jorgen and the other fairies laugh.]
Jorgen: Hahaha, funny, hahaha! [realizes what the April Fool said] Hey!
Jorgen: I fear we will never know who's was knocking, but I will make it my mission in life to find out!!!
Jorgen: [grabs the April Fool] Ah, now tell me who was knock-knock knocking!!!