Hint 1
It sounds like you're on the right track. The lizard is locked in place while the moth travels but is there anything in the level that you could cause to move during that time? If you want to revisit it, the level you're remembering is Glimpse in the Snow area.
Hint 2
If you're struggling to get an obstacle between the light and the moth, could you instead get the light itself to move out of the way? The second moth will be helpful here.
