What is a "scutella of reindeer"?
Scutella refers to shield or plate-like structure on animals (dictionary.com), such as the scutes of a turtle shell.  I have never seen reference to scutes or scutella or anything similar on any type of deer, including reindeer. 

I have not seen the movie so I do not know the context of usage. My gut reaction is the person was trying to make something sound important or "scientific" when a much simpler (and perhaps more accurate) word would have sufficed.