These unidentified lizards are from another dimension, they are large reptilian predators that which attack their prey with their powerful jaws as their possible primary use of attack mechanism. They inhabit a volcanic environment which Nightcrawler often travels through whenever he teleports and hardly noticable by the native fuana, until when an experiment to explore the dimension gave the predators an advantage to break into their universe in Bayville High and the Xavier Institute, using the rifts from Forge's experiment a year earlier. A few of them ambushed the students in highschool during a school dance but were sent back to their native dimension by the X-Men, sealing the rifts once and for all so they would never return.
These creatures made an appearance in the X-Men: Evolution episode "Shadow Dance". They have not been given an actual name by the creators.