Grandpa Sawyer/3D Timeline

Grandpa Sawyer is the grandfather and oldest living member of the Sawyer Family. He is a former butcher/slaughterman and mass murderer. He is a supercentenarian and is kept alive by drinking the blood of his family's victims.

Biography
Grandpa was originally a worker at a slaughterhouse whose skills at killing and butchering cattle were unmatched. After modern machinery was implemented at abattoirs for butchering animals, Grandpa retired from his work, ashamed. Even decades later, the Sawyer descendants regarded slaughterhouse machinery with disdain. Grandpa apparently settled down with the unnamed Grandma and began a family, the cannibalistic Sawyers (how they became cannibalistic is never revealed, though it is implied that they resorted to cannibalism to survive starvation, because the family was already poor when Grandpa and the rest of his family quit working).

The Texas Chain Saw Massacre
Initially thought to be already dead; he is first seen briefly during Leatherface's chase scene, Sally approaches him seeking help but assumes he is dead when she sees how old he is. Later after heroine Hardesty Sally Hardesty is captured by his grandchildren, Drayton, Leatherface and The Hitchhiker, Grandpa is taken from the second floor of the house and brought to her by them. Leatherface cuts Sally's finger and forces it into Grandpa's mouth, so he can suck her blood, an event that causes Sally to fall unconscious. Sometime after Sally is awakened, Drayton, Leatherface and the Hitchhiker decide to allow Grandpa to end her life using a hammer; due to his advanced age, Grandpa is largely incapable of using the hammer efficiently and continues to drop it. The hassle that ensues with Grandpa's continued dropping of the hammer and his grandchildren's over-eagerness to help him allows Sally to break free of the Sawyer family and jump out a window, though he and Drayton do not attempt to follow her.

Texas Chainsaw 3D
Grandpa was at the Sawyer house the day after the massacre when Sheriff Hooper came to arrest Leatherface. This time Grandpa was holding a cane rather than wheelchair-bound. When vigilantes attacked the house, Grandpa was shot and was inside the house when it burned down, dying with most of his family. Presumably he was buried on the Carson property with his other relatives.

Leatherface
Grandpa is shown in the 1950s with a youthful appearance compared to the original film. When a young Jedidiah is presented with a chainsaw and forced to torture a man who they've accused of attempting to steal one of their pigs. Jed refuses and the thief is killed by Grandpa. He is not seen that much during the film after this.