You were supposed to be watching him!
Jason is the main antagonist of the Friday the 13th film series, only ever sharing the spotlight with Freddy Krueger in Freddy vs Jason. In life he was a hideously disfigured boy, who his mother Pamela kept away from the cruel outside world. One summer while unable to find a baby sitter for him, she brought Jason to her work at Camp Crystal Lake. There he was bullied by the other campers, who pushed him into the lake. Unable to swim, he drowned as the counselors tasked with watching the lake were in the woods having sex. This lead to the closing of Camp Crystal Lake.
Kill, Jason. Kill for mother.
The death of her child left Pamela Vorhees stricken with grief. The year after Jason drowned as Camp Crystal Lake was slated to reopen, Pamela took revenge into her own hands killing the counselors present at Camp Crystal Lake. As the saying goes, if you seek revenge you better dig two graves. This quest for vengeance ended in Pamela's death by the sole surviving counselor. As the survivor sat in a canoe, Jason erupted out and drowned her. Thus begins the epic of Jason Vorhees and his need to avenge the death of his mother.
Jason, my special, special boy.
Jason is an undead spirit of vengeance, unkillable and unstoppable. Because of his undead status, he has many powers some would consider to be...supernatural. He is virtually immortal, as his tissue can regenerate abnormally fast, and from any amount of tissue. He also feels no pain, for as a human adult he was able to withstand many beatings that would cripple a normal human. In death, not even a severed arm will stop the Revenant of Crystal Lake from killing campers.
Do you know what your gift is?
Jason no longer feels pain, not as humans do. The only pain he feels is the loss of his mother. Near Crystal Lake he holds an altar that holds his mothers detached head and sweater, where he piles his victims. The reason for this is unknown, but it is thought he does this in an attempt to please his mother as if him bringing enough bodies will bring her back to him. This could point towards his source of resurrection, as if this will please a greater entity to bring back his mother as they brought him back, meaning Jason has some sort of faith.
No matter what they do to you, you cannot die.
Interestingly enough, Jason has a soft spot for children and pets. He will not harm a pet or a child under 13. His inability to kill a child stems from his own death, having him sympathize with the plight of children and not wanting to share his fate with them. He doesn't kill pets because to quote Kane Hodder "Jason has no qualms about killing humans, but he's not bad enough to hurt animals".
You can_ never_ die.
Jason Vorhees has the highest kill count of any slasher at at least 166. The next few are Michael Myers at 81, Freddy Krueger at 60, and Chucky at 48. He can be stopped my common sedatives. He can be revived by the following: Lightning, Psychic Powers, the death of his mother, and sexual acts.
Here's hoping the delay post thing works!