Lauren Faust has made it abundantly clear that she is not at all proud for writing "Everyone Knows It's Bendy."
Tara Strong has said that Terrance was her least favorite character to play, as his raspy voice made her go hoarse with each appearance.
Creator's Favorite Episode: Mac's voice actor Sean Marquette cites "Partying is Such Sweet Soiree" as his favorite episode, specifying that he really enjoyed getting to perform the role of Mac while his character was running around screaming like a maniac from his sugar high.
Dawson Casting: Eight-year-old Mac is voiced Sean Marquette, who was about fifteen or sixteen when the show began. He was not replaced after he had gone through puberty. Instead, he had his voice digitally pitched up. It is obvious if one compares episodes from Season 1 to episodes afterward.
Fake Brit: Kansas native Tom Kane as Mr Herriman, who has a British accent even if he probably isn't actually British. He mostly pulls it off, but certain pronunciations may give the game away.
Follow the Leader: While not the first TV series to use Adobe Flash for it's animation, it was arguably the first to push it's limitations to better suit the looser appearance of traditional character designs instead of the blocky, geometric look often used to make Flash animation easier, and has clearly had an influence on television fully embracing the medium over the following decade in shows like My Little Pony: Friendship Is Magic and Motor City.
Inspiration for the Work: The inspiration for the show came from when Craig McCracken and Lauren Faust adopted three dogs from an animal shelter, and wondered what their lives were like before.
Out of Order: The episodes on the first season DVD set are listed differently than how CN aired them, as they go from production order. This makes sense as "Busted" feels like it takes place after "House of Bloo's".
Screwed by the Network: A minor example, but the reason why "Everyone Knows It's Bendy" ended up being such a disappointment to the writing staff. Before the episode was finished, Cartoon Network insisted that the series switch from half-hour to quarter-hour hour shows and the result was that several key story moments, which would have ended in Bendy and Bloo getting what they respectively deserved, had to be dropped.
A character originally conceived for the show was an imaginary friend who was created from the acid trip of a college student. However, Craig McCracken had no idea how to convey it subtly before realizing he didn't want to know what kinds of imaginary friends an adult could create, hence the rule that only children can make imaginary friends.
Word of God: Years after the show ended, the show's creator provided numerous odd bits of information on Twitter:
Write Who You Know: Frankie is based on Craig McCracken's wife and series writer Lauren Faust. He denies that Mac was based on himself, but seeing as Mac has a crush on Frankie, Craig eventually decided to roll with it. The concept came to him when he and Lauren adopted a puppy and Craig made up a story about what his life was like before they got him.