Austin - Fred.
Fred is a stuffed bear given to him by Bri. She gave it to him as a gift, in which he responds by throwing it over a wall. Bri was upset by this, before learning that he never meant to get rid of it, but to rather keep it for himself. Austin and Bri both have a stuffed animal, and Austin would never want to see Bri sad.

Bri - Stella.
Remember when I mentioned Bri and Austin having stuffed animals? Well, Bri's stuffed animal is Stella, a stuffed rabbit that kinda looks like her, minus the white. While this was extremely debatable with candy, we've seen Bri avoid candy for a couple of episodes. However, without Stella, Bri may go insane.

Brick - His headphones.
While Brick has only uploaded one episode for OriginZ, we know he wears his headphones a lot. Kinda curious as to what music he listens to? An alternative to this may be his personality, but that's not an object.

Bryan - His farm.
Bryan has a farm that him and safe haven uses throughout the series. Without the farm, everyone would starve, or have to live off rotten flesh. Which, mind you, isn't that much of a good idea.

Colin - Candy.
Now you know why I reserved Bri. But yeah, other than his previous video games, Colin would pretty much die without his candy.

Cordelia - Her meds.
Without her meds, Cordelia will go insane, and will go on ahead and call Michael's hideout an "Italian restaurant" and will just go crazy whenever the doc tries to flirt with her. With these meds, she ends up being the one who flirts with the doc and keeping herself sane.

David - His axe.
"Sharp weapons save lives" was the motto he made up. He would spend his free time sharpening his axe, taking care of it, and literally angering Lucas with this stuff. Without his axe, David would go crazy. Absolutely crazy.

Devin - His money.
We all know Devin's original plan was to grow up and become a professional banker. But instead, the apocalypse happened so he's now doing all of this banking stuff in private. We all know what he'd do without his money: either shoot himself, or just loose his mentality.

Inmo - His Mask.
Like Leo, Imno gets around zombies with his mask. and even though the dude doesn't know who he is half the time, he's still able to keep his conscience because he has his mask.  (It's also likely the virus is airborne, or Inmo is just crazy.) Without it, Inmo wouldn't live to see the early dawn, if not the moon rising.

Johnathan - His plants.
Johnathan's a professional planet we. He plants for the main fold source, and makes sure everyone else is well fed. When he joined the misfits, he planted for them as well, making sure everyone was able to be fed.
Without plants to even begin with, Johnathan would probably feel as though he's been a failure his entire life. He'd either leave the misfits or allow himself to be infected.

Justin - His Necklace
Justin has a necklace he wears 24/7. It was a gift given to him by Willy Ray Steward, or Mr. Montana. Justin's Mr. Montana's son, who lives his life knowing his father is dead. It's as if the necklace (which is an eighth note) is what's left of his father- as if his father IS the necklace.
Without it, Justin will surely commit sharp object in head/heart because of how valuable the necklace is to him.

Kayla - Her mother.
Kayla has been keeping her mother hidden from just about anything, despite her mother being a zombie. Kayla has a heart for zombies and refuses to kill any of them, due to her mother, but as well as her putting herself into other's shoes.
Without her kit her, Kayla wouldn't commit suicide, but rather have a zombie infect her so she could join her mother in the "afterlife."

Kaylee - ???
We'll probably figure out what she holds dearest to her when the time comes.

Leo - His mask.
Brandon, or Leo in OriginZ uses his mask to get around zombies. He uses it as a disguise in order to carry out a part of his and his friends' plan. Without his mask, here would be huge drawbacks to their plans. And getting food, would be almost impossible.

Lucas - Food.
In a way, Lucas is the food supplier of the gang. He makes sure his gang is able to keep up with their food stock. If they're running out, they raid some random place. Without food, Lucas and everyone he ever met in his life would die. And I'd rather have Lucas die later in the apocalypse, if not never. But hey, he's with Leo and David. He has a good chance of dying.

Mario - His truck.
Mario gets around the place in his truck. He sometimes crashes in it for the night when it's too dangerous to camp out, or used it for storing his armor and weapons. He also sometimes uses his truck to get out of Safe Haven's radar and hide away from them. Because let's all admit it. Safe Haven? More like DEATH Haven!

Marshie - ???
We may know as time goes on.

Michael - Bombs.
He blows up stuff with these guys. And with these guys, he goes mentally insane and tries to kill everyone and everything. Seems appropriate he'd actually use him a as a way of life.

Nick - His gun.
He shoots everything. He's a fighter. Fear him.

Nicoline - Her dog.
I'll deny the dog is dead, thank you.
Nicoline has a dog that she brought with her when she went here. However, because of the zombie outbreak, she was unable to return. Instead, she made some friends and stuck near them. Without her dog, she's fall into a deep depression. In fact, she may never get out of the grieving stages.

Pat - His guns.
Colonel Ironwood carries a crap ton of guns around, which is pretty much why he went insane. He went out of his way to make sure all of his guns are safe at the end of the day. He doesn't care if he isn't leader of Safe Haven anymore, since his sanity is less than Michael's. (In a way.)

Ritchie - Brains.
What's separates Ritchie from other zombies is the fact he isn't technically a zombie. Instead, he's a half face, meaning he maintains his personality, appearance, and most of his control despite being somewhat a zombie. If he doesn't eat other people's brains, he'd turn into a zombie. Which would mean, it'd be the end of the world. Probably.

Seek - Ducky.
Seek talks to a duck. A rubber duck.
Without this said duck, Seek would be screwed.

Xylo - His gun.
Of course, Xylo's an actor. And even though a camera would've probably suited this well, it wouldn't really work. Xylo uses a gun for protection. Not only to himself, but to others as well. Without it, he'd probably feel as if he's failed everyone else.

Zachary - His Backpack.
Zachary's backpack is the last thing that keeps his sister alive. His sister, Sophie, died in a car accident on their way to the hospital. (This may be corrected, since there's a theory stating Sophie turned into a zombie instead.)
Without it, Zachary would definitely commit suicide. Him and Justin have a lot to relate to.

Zaro - His gun.
Zaro is the sheriff of the town. He may use his gun whenever he needs to, and will only do it to make sure the area he's protecting is safe from any attacks. It's only fair he uses his gun for his daily life.
Without it, he'd surrender his badge. Which means he'd be useless and the zombies will eat his head. Don't loose your head.

Huge, huge, HUGE thanks to my crush for helping me with this!