The Riz was a devotee of Bugs Bunny with an encyclopedic knowledge of Bugs and his history. Since Bugs was the creation of many (not just Chuck Jones) and repeated his mannerisms, like breaking the fourth wall, and the repeated use of ‘What’s up Doc?’ it was fair that The Riz used references from older Bugs cartoons to establish Bugs’ true identity and be faithful to the myriad cartoonisist that worked o the material. Here are a few examples:
This:
And this: