Mobs becoming invisible/glowing ghosts at night

After I placed lava down, I experienced a lag spike and I observed several cows glowing, I keep trying to duplicate this glitch, but it was unpredictable, it only happened after the lava was placed. It only happened for some mobs at specific distances though. All mobs in the vicinity were observed to glow, blazes however, have more of an outline, but never became transparent. It usually occurred near the edges of the screen.