Spike was the canine companion of Fiorina "Fury" 161 Class C Work Correctional Unit inmate Thomas Murphy. He was impregnated by a Facehugger that arrived on the planet on board the USS Sulaco's EEV, and later died birthing a Runner.
After the EEV that brought Ellen Ripley to Fiorina 161 is recovered, Spike confronts a Facehugger hiding in the wreckage and is attacked and subdued. Murphy later found Spike in his room, his face lacerated from his struggle with the Xenomorph creature, mistakenly assuming one of the other inmates had attacked him out of cruelty. While the prisoners were attending a funeral service for the deceased Newt and Turk, the Runner that had been gestating inside Spike violently emerged, killing the dog before it escaped into the prison's ventilation shafts.
- Spike is a Rottweiler.
- The Assembly Cut of Alien3 removes Spike completely. Instead, the Runner gestates inside Babe, one of the prison's oxen (which are never seen in the theatrical version). Spike is also absent from the novelization of the film, which follows the Assembly Cut's plot as it was written before the film was altered to the theatrical version.
- It is not clear how Spike came to be in Murphy's care on Fiorina 161 as prisoners would not be allowed pets, especially not a dangerous dog like a Rottweiler. It is possible Spike was a previously guard dog at the prison, left behind when the facility officially closed and subsequently adopted by Murphy.
- In the comic adaptation Spike is known as "Sparky".