Pancho Billa died Tuesday after a long fight, but those who knew and admired him are carrying on in his memory.
The Texas resident, whose real name was Ezra Castro, passed away Tuesday following a fight with cancer.
He spent the past few weeks in hospice care.
In true Bills Mafia fashion, fans are donating to Roswell Park Comprehensive Cancer Center in memory of Pancho.
A spokesperson said the Roswell Park Alliance Foundation has received dozens of donations from across the country in Ezra Castro's name to support research, education and patient care programs.
Pancho made a name for himself at Bills games over the years, dressing in a big sombrero and luchador mask, all in the red, white and blue colors of his favorite team.
Pancho's family tweeted the news, saying he was surrounded by his loved ones and they're forever grateful for the love and support they've received.
The Bills released a statement expressing gratitude for his dedication and sympathy for his family.