Talk:Papyrus and Sans's House/@comment-26521006-20151025145644/@comment-97.123.146.85-20151110185730

According to Purdue OWL:

Once you've determined whether you need to make a possessive, follow these rules to create one.

James's hat (James' hat is also acceptable. For plural, proper nouns that are possessive, use an apostrophe after the 's': "The Eggleses' presentation was good." The Eggleses are a husband and wife consultant team.)
 * add 's  to the singular form of the word (even if it ends in -s):the owner's car