Creator Alex Hirsch stated that series writer Jeff Rowe inspired Agent Trigger's character design.
The code in the credits translates to "Welcome back." The keyword is "Widdle", found on a wall in Gideon's cell.
The whisper heard during the show's logo has been changed to "Key Vigenère" backwards.
Beginning with this episode, the code in the credits changes to the Vigenère cipher, which can be decoded by a secret keyword showing up in one scene every episode.