Din Djarin is a human Mandalorian bounty hunter, created by Jon Favreau and played by Pedro Pascal in The Mandalorian from 2019. StarWars.com describes him as "a battle-worn bounty hunter, making his way through a dangerous galaxy in an uncertain age" — a deliberately small description for a character who ends up deciding who rules Mandalore.
A foundling, twice over
He was born on Aq Vetina and orphaned in a Separatist attack during the Clone Wars, then taken in and raised by the Children of the Watch, a hardline Mandalorian covert on Concordia whose creed forbids ever removing the helmet in front of another living being. That rule is the show's central mechanism. It is what makes him unreadable, what makes his few unmasked moments enormous, and what eventually gets him expelled from his own people.
The job he does not finish
The series opens with a straightforward premise: a hunter takes a lucrative contract from an Imperial remnant client to retrieve a fifty-year-old asset. He delivers the target, an infant of Yoda's species, and then within a single episode goes back and steals it again. Everything afterwards — the flight from the Guild, the search for a Jedi, the war over Mandalore — follows from a professional deciding that the contract was wrong.
The Razor Crest and the trade
He flies a pre-Empire gunship called the Razor Crest, carries an Amban phase-pulse rifle, and works through the Bounty Hunters' Guild via Greef Karga on Nevarro. The first season is essentially an anthology about how bounty hunting actually functions in the ungoverned Outer Rim five years after Endor: carbonite freezing, tracking fobs, guild protocol, and the fact that nobody in the New Republic is coming.
The Darksaber problem
In defeating Moff Gideon he wins the Darksaber, the blade that Mandalorian tradition says can only legitimately be held by someone who takes it in combat. He does not want it, cannot use it well, and cannot simply hand it to Bo-Katan Kryze without voiding the very tradition that makes it worth holding. Season three resolves this the only way it can — by having him engineer a fight he intends to lose.
Redemption by immersion
Having removed his helmet in season two, he is cast out and can only be restored by bathing in the Living Waters in the mines beneath Mandalore — a planet the Empire is supposed to have rendered uninhabitable. The journey there is what finally forces the scattered Mandalorian factions into one room. He ends the season having formally adopted the child as Din Grogu and retired to Nevarro.
Why the helmet works
Casting an expressive actor and then covering his face for almost every frame is a strange decision that critics questioned at the time. It works because Pascal plays the body and the pauses, and because the creed makes the concealment mean something. A mask you cannot take off is a promise, and the whole series is about what happens when you break one.