Sam

Sam (aka SAM), a flying drone bot capable of opening doors and hacking computers. Together she with Bravo Marne, the survivor of an initial incursion at Mars City in June 2145, made their way through the Mars facility, and even Hell (Gehenna and Abaddon), while battling zombies and demons on his way through the base.

She sacrificed herself by jamming a closing door so that Bravo Marine could escape. She left behind data intel for Marine to pick up that would expose UAC's unethical experiments.

Sam's crushed remains ("SAM's remnants") were teleported back into hell back in Abaddon, where they were recovered by Stan Blazkowicz, O' Riley or Major Morgan. Sam's Remains are the last secret to find in Doom II RPG.