The Glimmer was related to the Hunter γ (Hunter Gamma) which were based on combining human and amphibian DNA. It's likely that their existence stems from the fact that the
Hunter Elite was also developed around the same time. However, the
Hunter Elite looked to be almost complete whereas the Glimmer was either quite early in development or abandoned.
They were quite a disgusting creature with a frog-like body but with many eyes above its mouth; because it had so many eyes, it was extremely sensitive to light and as such preferred to stay in dark, gloomy areas. As it was designed to constantly be on the hunt to feed, it also vomited vast amounts of strong stomach acids to help it digest its meals very quickly. It could also use these acids as a defence mechanism.
Their most common attack was to lunge at their prey and projectile vomit its stomach acids onto their victims faces, aiming for a quick death. They were alarmingly fast which was possible as they grew to be roughly half the size of a standard Hunter γ.
Their name may be something to do with the fact that they cannot stand light, only a glimmer would suffice. Also, the word is quite similar to how Gamma is pronounced in English.