Then it's pretty harmless for a demon, unless it wants to kill someone by plugging his nostrils, and then it would take two, and the person could still breathe through his/her mouth.
Or unless it has magic. Every small, frail creature becomes suddenly formidable if we learn it has magic. And demons would most probably have magic powers, that star may even be a pentacle drawn in blood, it's just hard to tell because it's so small...
Sorry, I'm not the right person to be reassuring.