They're not Nightcrawlers but "Bamf" demons. Beast mentions in issue #1 that he had trouble closing a dimensional portal and has let escape some intradimensional entities, which are clearly running amok around the school. If you'll look closely, you'll see that they are actually too small to be Nightcrawlers. What they are exactly and what their relationship is to the Nightcrawler of Universe 616 remains to be seen.
On a side note: in the picture Cyclops looks a little constipated. I just hope he doesn't have an aneurism... : )