|Hop hop hop like a bunny do|
— - The Hop Hop Bunny
The Hop Hop Bunny is a rabbit that Mario highly dislikes for being associated with a song that he also hates.
The Hop Hop Bunny first made it's appearance in the form of a cute cartoon rabbit in Jeffy's Favorite Song!, then it later appeared giant and nightmarish, and it was a type of antagonist for Mario in that movie.
At the end of that same movie, Mario has a nightmare about the bunny becoming demonic, and eventually eating him.
The Hop Hop Bunny is a very cute and nice bunny in the song as it is only in a cartoon, but at the end of the episode, Jeffy's Favorite Song!, and Bowser Junior's 8th Birthday!, it is demonic and evil, and kills Mario for disliking it's song.
The Bunny Do
Happy Birthday To You
His "The Bunny Do" song
Hey, kids! Do you wanna hop like a bunny? Well good, 'cause we're about to hop 'til you drop, so don't you stop! Okay, here we go...!
(singing) Ohh Hop-Hop-Hop like a Bunny do!
And Hop-Hop-Hop like they always do!
Hop-Hop-Hop like a Bunny do and!
(singing repeated 4x)