The way Grug's stilts are descending from the macawnivore pawing them down and attack Grug to make him jump in fear and pain is similar to Yosemite Sam's predicament with the Roman lions.
Bill introduces this Bugs Bunny/Yosemite Sam cartoon set in Ancient Rome, and notes that the characterization of Nero is based on Charles Laughton's portrayal of Henry VIII in the film "Young Bess".