Moze was originally a soldier in the Vladof army's Ursa Corps, a mechanized infantry division that utilized bipedal, 15-ton "Iron Bear" mechs. She became a battle-hardened veteran of many ludicrously dangerous battles across the six galaxies and rose to the rank of Gunner First Class. According to the terms of her enlistment contract, she was obligated to fulfill a quota of missions for Vladof before quitting if she wanted to take her mech, Iron Bear, with her. Moze's superior, Kaziak, manipulated her into staying on longer by constantly extending the quota and playing on her guilt with claims that her absence would jeopardize the lives of new recruits who depended on her experience, much to her chagrin and anger. Moze finally decided to quit after one final mission to Darzaran Bay. The rest of her squad perished, leading to Vladof assuming her death as well. With the pain of losing her squad still fresh, she trusts only her mech, whose insides are dotted with photos and memorabilia from her past. After striking out on her own, the rising costs of maintaining Iron Bear eventually pushed Moze to travel to Pandora and seek treasure as a Vault Hunter with the Crimson Raiders.
- Main article: Moze/Skill tree
Moze's Action Skill summons Iron Bear, her mech. It comes with its own health pool consisting of armor. Iron Bear is capable of sprinting and jumping, and can perform a double jump that allows it to hover and gain momentum - continuous use of double jumping allows for movement speed that is faster than normal sprinting. Pressing the melee button will cause Iron Bear to do a powerful stomp that damages enemies around the mech. While in Iron Bear, Moze cannot crouch, slide, grab ledges, slam, use emotes or revive teammates.
Iron Bear possesses a fuel bar that slowly drains while the mech is active and using its main weapon depletes fuel. Other actions (including its melee stomp) will not consume fuel. Weapon fire rate also affects fuel consumption. If either the fuel bar or the health bar is depleted, the action skill will end.
The base cooldown time of Iron Bear is 110 seconds. Holding the crouch button will eject Moze from Iron Bear, refunding an amount of cooldown proportional to how much fuel was left in the action skill.
All of Moze's action skills are weapons that can be equipped on Iron Bear in various combinations. She has a total of six action skills divided between three skill trees, with each tree having one action skill available initially and one more that can be unlocked. Iron Bear has two slots for action skills, and either two different action skills can be equipped, or one action skill can be equipped in both slots. Moze's skill trees and respective action skills are:
- Shield of Retribution
- Bottomless Mags
- Minigun (initial)
The Minigun rapid-fires rounds and is capable of sustained fire. Firing the weapon for prolonged periods causes it to overheat and become inoperable for a short time.
- Salamander (unlockable)
A flamethrower that deals incendiary damage. It can be fired indefinitely without overheating or needing to reload.
- Minigun (initial)
- Demolition Woman
- V-35 Grenade Launcher (initial)
The V-35 is a semi-automatic grenade launcher. Projectiles bounce and will detonate after a short delay, or upon contact with a target. Despite firing grenades, its projectiles are unaffected by Moze's grenade mod.
- Vanquisher Rocket Pod (unlockable)
A rocket launcher that can rapid-fire unguided explosive rockets. It automatically begins reloading whenever it is not being fired.
- V-35 Grenade Launcher (initial)
- Moze was leaked prior to the game's announcement in December 2018.
- Moze appeared in a tech demo in which she had her face concealed and Randy was "teasingly" telling the fans that she will be a character in Borderlands 3.
- Moze's code name was "Iron Bear". Her infantry division, the "Ursa Corps", translate to "Bear Corps" in Latin.
- Moze is voiced by Cyber-girl Siro, a known Japanese Virtual YouTuber, in the Japanese dub of Borderlands 3.
- Moze's character class, a Gunner, is the successor to the Soldier and Commando classes from previous games in the series.
- Moze has the Vladof logo tattooed on her hip. Her English voice actor, Marissa Lenti, had the tattoo re-created in the same spot to commemorate the role.
- Moze has an affinity for fried food, and is apparently very open to trying delicacies so long as they are deep fried.
- Moze wears a digital watch on her wrist that accurately tells the time of the planet she is currently on. The amount of time that passes during each real life second is dependent on where she is.
- During The Great Vault story mission, the watch will speed up and this persists until a new playthrough is started.
- According to her dialogue in Pandora's Next Top Mouthpiece, Moze "digs [Tyreen's] coat".
- According to her dialogue in Guns, Love, and Tentacles, Moze's worst fear is exploding bees, as "there's just a buzz, and then a boom".
- One of Iron Bear's skins prominently features a half-naked pin-up of Axton, one of the playable characters from Borderlands 2 who has since become a model.
- Any skin and color combination that is applied to Moze will also be applied to Iron Bear.
- Moze's full name is revealed during The Family Jewel, while responding to BALEX' description of his name's origins.
- If in a co-op game that has Amara, Moze may let slip that she "Loves [her] arms" when she uses one of her action skills. She then grows quickly flustered and changes the subject to the war they're engaged in. It's unclear whether she is referring to Amara's actual arms (which are muscular) or specifically her siren arms since it only triggers when those are used.
- According to various articles, she flirts but is not ready to open up. She’s not altered by the trauma of battle, but by losing the structure of military life, which is the cause of something being "a little off" about her. She’s most comfortable in the throes of battle, during which she laughs constantly. 
- She likes her Iron Bear. pragmatism, preparing for everything, and chewing gum. In fact, she has a balled-up piece of gum for every battle she’s ever been in.
- She hates the unknown and people who don’t know what they’re doing and doesn’t like standing still and has to be doing something. When bored, she starts repeating the words from military drills.
- She is in her mid-twenties.
- In Guns, Love, and Tentacles, Moze lets slip that she reads “paranormal romance novels.”