Now that Miranda has confirmed that he will exit the play in July to be replaced by his alternate Muñoz, fans are clamoring to know more about the actor.
Muñoz has tried to mostly keep his health battle private (he hasn't revealed what type of cancer he had), but shared that he had been treated after his illness caused him to miss several weeks of performances last year.
He has said he didn't even tell his parents when he was initially diagnosed -- despite the fact they are both cancer survivors.
"I was very ... I don't want to say proud, because it wasn't pride," he told People in March.
"It was looking at the mountain and thinking, 'I can't take anyone up this with me. I think I have to meet people on the way.' ... No one can give me that fight. I had to find it in me."
The experience shook him, said Muñoz, who has since recovered.
"It's a rare thing in my life to find myself face to face with something I'm scared of, and I was scared of this," he said. "I had never been more scared in my life."
He grew up poor
The Brooklyn native came up the rough way, telling the New York Daily News in 2009,
"we grew up relatively poor in a first-floor apartment with gates on every window. It was scary coming home, because it was a rough and violent neighborhood."
He helped create the 'Hamilton' role
In welcoming Muñoz in taking over the role, Miranda said as part of a tweet "We created the role together."
That's because the pair worked on sketching out what would become the hip-hop version of Alexander Hamilton. The actor told Vulture
he got a call from his friend Miranda asking him to come on when it was still being envisioned as the "Hamilton Mixtape."
"Obviously, I'm gonna say yes," Muñoz said. "Let's get in the room and see what this is. It was just a collection of songs at the time. And I joined from that point forward."
It's not his first time taking over for Miranda
Muñoz has a history of filling Miranda's shoes and filling them well.
In 2009 he stepped up from acting as Miranda's understudy as Usnavi in Miranda's first successful musical "In The Heights" to take over the role.
Muñoz said at the time that he worried about disappointing Miranda.
"My greatest fear is not living up to Lin's expectations and the faith he is putting in me," he said. "He is so charming and likable and creates an immediate relationship with the audience every night."
He need not have been concerned, however, as Miranda told the New York Daily News
, "Javi played 'Usnavi' in those crucial moments when I needed to step out and watch the show as composer."
"He's evolved in tandem with the role," Miranda added. "I'm proud to be handing the hat over to such a talented man."
He's known as the 'sexy Hamilton'
You can thank New York Times critic Ben Brantley for that distinction as he started a 2015 story
about Muñoz's "Hamilton" performances with the line "Alexander Hamilton is sexy on Sundays" before going on to describe the actor as having a "penetrating stare and a Don Juan smile."
Muñoz also won raves from Brantley for his performance.
With all that, it's not hard to understand why #Javilton became a thing on Twitter.