The young man in a photo that's whirring around the Internet grins broadly, gently cradling a cat that clings to his sweater.
He's thought to be a US citizen, who went by the alias Abu Hurayra al-Amriki.
According to the al-Qaeda-backed group called the Nusra Front, this young man blew himself up for their cause on Sunday in Syria's northern Idlib province.
Aryn Baker, Time's Middle East bureau chief, says the young fighter is a bit of a mystery.
"We don't know if he was American-born, naturalized, or where he came from," Baker adds.
An estimated 70 Americans are fighting with Syria's rebels, along with several hundred Europeans. Many of those westerners who travel to Syria to join the civil war are welcomed into Syria's most extreme rebel factions, because those groups are well-organized and open to accepting foreign fighters.
In addition to the rebel fighters, a handful of Americans are apparently fighting on the side of Syria's President Bashar al-Assad. Baker met one Assad recruit recently in the city of Homs. He was from Baker's hometown in California.
"It was a very surreal accent to be hearing as I walked down the completely bombed out city," Baker recalls.
On social media, Syrian extremist groups are sounding triumphant about Sunday's suicide bombing and the man allegedly behind it.
"They're vocally claiming that they have an American, the first American," Baker says. "They keep repeating that. It's quite a coup for them. "
The prospect of Americans receiving training from extremist groups in suicide bombing tactics raises troubling questions, especially as the US government contemplates whether to provide more aid and even weapons to Syria's rebels.
"The big fear now is that you'll have some people going (to Syria) with the intention of perhaps blowing themselves up in Syria to further the cause — but who may have been talked into changing their focus and returning to America to attack US sites," Baker notes.