Family Name Pluralization
What is the plural of Santa Claus? It would be Santa Clauses, right? I started with Santa Claus' but that's obviously not correct.
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The plural of Santa Claus is Santa Clauses. See this guide on unusual plurals for example.
Santa Clauses. Since Santa Claus is a proper noun, it's capitalized, thus differentiating it from Santa clauses, which is maybe where you're getting confused. Other than that, it's up to your discretion to make the distinction. That's the English language for you...