Final answer:
The provided sentence is testing comprehension and vocabulary in the English language, requiring a noun to complete the joke about a substitution in a dance scenario.
Step-by-step explanation:
The sentence provided appears to contain a blank that should be filled with a noun. The context of the sentence relates to a substitution in a dance, which implies a comical or metaphoric scenario that Jack is suggesting.
Given the structure of the sentence, Jack might be implying that something else, probably less significant or smaller than a pig, could be 'killed' or sacrificed during their dance in a figurative sense. The word needed to fill in the blank could be based on the specific context of the joke Jack is making, which isn't provided here. This type of question is typically designed to test comprehension and vocabulary skills in the English language.