Samantha (also known as Sam) is a dog and Robert Neville's only living companion. She is played by two German Shepherd Dogs named Abbey & Kona.
On the night that Robert Neville attempts to evacuate his wife and daughter from the city, his daughter hands him Samantha - then still a puppy - and tells Samantha to look after her dad.
Following the mass evacuation of the city, its isolation - by the destruction of bridges - and the ultimate death and/or infection of every other human in the city, Samantha becomes Robert's sole companion. Throughout the movie it is seen that Robert's bond with Sam is almost human, as he talks to her like a human friend and even feeds her food off of a plate and later berates her - in a loving way - for not eating her vegetables.
Sam accompanies Robert where ever he goes, including on hunting trips. In one tense moment Sam follows a deer into a dark building while hunting and has to be rescued by Robert from a "hive" of Darkseekers.
Heroic fight, Infection and deathEdit
Robert, even though he has Sam for company, clearly shows signs of isolation and the need for human contact as he talks to mannequins and even implies attraction to a female mannequin in a video store. He apologises to Sam for not chatting to the female mannequin, but promises to build-up the courage to do so. While out driving Robert comes across "Frank". He exits his vehicle and becomes angry with "Frank" because "Frank" has moved by himself. He proceeds to shoot the mannequin. He is immediately overcome with grief by his actions and walks over to "Frank". It is then that we realise that "Frank" was placed there as a decoy by Robert as when getting near "Frank", Robert triggers a similiar snare to the one he set to catch the female Darkseeker he is using for anti-virus tests. Robert is knocked unconscious after hitting his head when the snare lifts him off the ground.
Robert is later woken by his watch beeping - warning him that the sun will set soon - and Sam crying and licking his face. Rober