In modern Christmas folklore, Santa's elves are often portrayed as speaking a unique language called "Elvish" or "Elfian." It's important to note that this language is not a real language but a fictional one created for Christmas stories and movies. Different Christmas stories and movies may depict Santa's elves communicating in Elvish in varying ways, with different vocabulary, grammar, and pronunciation. Some stories may not even address the language that Santa's elves use. It's worth mentioning that the concept of Santa's elves as we know them today is a relatively recent creation. The depiction of these elves speaking a specific language is not a consistent aspect of Christmas folklore.