Lacertilia suggests its a burrowing lizard, after you said it lives in caves i assumed this was the correct title. the first name, however: ilu = luminescence or ilu meaning beauty in Estonian. the crita I added is a little bit of creativity, or you could say it means Krita, which is Swedish for chalk referring to its rocky home and vibrant color.

the Lizard is SCP-049's idea

i know but wouldnt hurt add a bit of creativity!