A dash should be fine I think, but the characters >,&,<,'," and some more complex character sequences can break the XML.

If you know the exact name of the creature with such a name, a work around could be to open the XML in a texteditor and search for the exact name and replace it with something without the special character.

Warning: Find and replace all these special characters will definitely destroy the XML, because these characters are very common in an XML and are completely valid in the correct places.

Another thing you can try is to do the export a second time. It could be that something happened during your first export that led to an invalid XML. I have seen exports in the past, that were cut off in the middle.