Grid was a smooth-domed Xenomorph Drone spawned during the ill-fated Weyland Expedition to Bouvetøya. Grid was responsible for killing the Predator Scar's brothers and clanmates Chopper and Celtic, and was able to escape being shot by Scar's plasma caster attacks.
After easily ambushing and impaling a distracted Chopper, Grid gains the attention of Celtic, who becomes enraged, seeing his brother killed by the Xenomorph. A long engagement of single combat ensues between Grid and the plasma caster-less Celtic; during the battle the alien is caught in a net, which slowly tightens around its victim, shot by Celtic (hence its name), with Celtic appearing to have the slight advantage. Celtic manages to trap Grid in his net but due to Grid's acid blood, it escapes and jumps on Celtic and kills him with a bite to the head.
It then begins to stalk the remaining Predator, Scar. Grid and several other Xenomorphs catch up to Scar just as he gets his plasma caster back from Alexa Woods. As Scar began blasting alien after alien, Grid hid in the shadows to avoid the plasma blasts. When the Queen screeched for them to retreat, Grid and the other Xenomorphs returned to the Queen and released her by attacking her, allowing her acid blood to burn through the chains that confined her.
When Scar and Lex try to escape the pyramid, Grid chased them in the ice tunnel, but is too slow and is incinerated, crushed and buried by the self-destruct device explosion.
Though Grid is mostly shown to rely on primal instincts like its siblings, Grid seems to show some unique intellectual traits found in some individual Xenomorphs. For example, Grid helped free the Queen by cutting her open and allowing her acidic blood to burn away the chains that confined her.
Grid's nickname is derived from the grid-like scars it got after being caught in Celtic's net. A skin for the Alien is available in the video game Aliens vs. Predator (2010) for the PS3, Xbox 360, and PC but is known as "Nethead". The skin can be unlocked when players reached rank 34.