Cat breaks the fourth wall about Rancid Rabbit having multiple jobs, when he questions how could Rancid be a policeman if he was also the school principal.
Lube's nephew: Well, if it isn't the bicentennial quadruped commonly known as Catdog.
Cat: Are you sure you're related to Lube?
Randolph: It's Kooky Prank Day and I love it!
A character named Sally was featured in the episode "It's A Jungle In Here" as Cat's grade school crush, who went from being a "neat freak" to a "wild woman". However, in this episode, she's a teacher and was Cat's crush during high school. This may or not be the same person.
Dog: It's Kooky Prank Day Cat!
Kooky prank day is a spoof of April Fools day.