- " Ha! Giant flesh-eating dinosaurs or Billy Yoder...I'm not sure which sounds safer! "
- —-Daniel Cafaro "D-Caf" (src)
William "Billy" Yoder was a mercenary, and one of several sent into Jurassic Park on Isla Nublar after the disaster on the island, tasked by InGen to rescue the Hardings, Laura Sorkin and Nima Cruz from the area.
Hailing from San Jose, California, Billy Yoder appears to be in his late 20's or early 30's. He mentions having a step-brother who used to hide a second set of house keys in a fake soda can.
During the scene when Yoder refers to Oscar after he died, he says "a bunch of blue collar grunts". This has something to do with Oscar's death, but he could be referring himself as a dropout person during his life in high school. This also happens when he refers to D-Caf as "another throw away grunt", meaning this has nothing to do with Oscar and D-Caf's early lives before they died.
During the storm, most InGen personnel were evacuated from Isla Nublar. However, some people were left behind. InGen hired two teams of mercenaries to retrieve and rescue remaining Jurassic Park staff on the island. Yoder and Oscar were on the Alpha Team.
Upon arriving, he has a run-in with a Dilophosaurus after accidentally stepping on one of its eggs while trying to pick up the trail of the remaining survivors. Soon after, he and Oscar Morales begins rounding up the survivors. He meets a female employee, who informs him of the shocking events that happened at Jurassic Park.
Along the way he and Oscar meet the Hardings: Gerry, Jess, and the smuggler Nima Cruz. At first, he is sympathetic towards the dinosaurs, ordering Oscar not to kill a Dilophosaurus that he had wounded. But as time wears on his respect for them wears thin after seeing them kill his friends. He develops a rising resentment towards Laura Sorkin's motherly devotion to the dinosaurs, often contemptuously referring to them as her "freak show" or "pets" simply to spite her, and taking great care to emphasize that they will all be destroyed in the Napalm bombing.
His hatred for her rises continuously after the deaths of Oscar and D-Caf, and when she quietly reveals that she had known about the Troodon, he threatens to kill her, only to be stopped by Dr. Harding, Jess, and Nima - but not before forcing her at knifepoint to admit that everything had all been her fault.
After the deaths of his two best friends, he goes insane and betrays the group. He also decides to take the Barbasol can for himself, so that he would be paid for the embryos. He offers to take Nima along, but she is disgusted by his betrayal and refuses.
As Nima and Yoder fight over the can, Roberta approaches the group, and Yoder stands still. But Gerry, deciding to shift Roberta 's attention to Yoder, kicks the Barbasol can so that it would fall into the ocean. Yoder ran after it and managed to grab it just before it dropped. After he gets up, however, he only hears the grunting and growling of Roberta before she snatches Yoder. The Tyrannosaur proceeds to devour him.
If the player fails to complete certain tasks, it is possible for Yoder to be devoured by a Troodon, Tyrannosaurus, or a Dilophosaurus. These deaths are considered non-canon, and will result in a game over. The player will then be allowed to respawn and try again.
- Billy Yoder was the second human in the franchise (after Lewis Dodgson and before Eli Mills ) who tried to kill another human with his bare hands. However, unlike Dodgson and Mills, Yoder is considered tragic, and he never succeeded in killing anyone.
- He is the last mercenary to survive, but he gets eaten by Roberta at the end.
- It is implied that he gets very low pay for his job, which easily explains why he chose to take the Barbosal can for himself at the end.
- Yoder is a main human antagonist in the video game, although he only became an antagonist after snapping into insanity upon the deaths of his friends.
- He is named after a real life former actor.
- He resembles some of the hunters in the The Lost World: Jurassic Park arcade game.
- When he is on the phone making a call to an army official at the Marine Facility, he says that his name is William Yoder. "Billy" is an abbreviation of William.
- He is from San Jose, California.