And then there's Pancho Billa.
Ezra Castro wasn't from Buffalo. Born in El Paso, Texas, he latched onto the Bills as a kid because of their colors, with the red, white, and blue being the closest an NFL team came to those of the Mexican flag's red, white, and green — a celebration of his heritage.
Through the years, those colors donned Pancho Billa's sombrero, poncho, leather arm guards, and signature mask.
Pancho was a fixture in the front row at Bills games — home and away — despite residing in the Dallas area. When not in the stadium, Castro led the Bills Backers of the Dallas-Fort Worth area.
His spirit was infectious — even after being diagnosed with cancer in November 2017.
"It's not just his costume. His costume is just an extension of his personality. He never wore that costume to call attention to himself. If you ever went to his house, ever saw him, ever followed him around, you'd see that every single thing he does — right down to the socks he wears — he's just all about his team," said friend Ken "Pinto Ron" Johnson.
As Castro battled through surgeries and treatment, his support for the Bills remained strong, as the Bills’ support for Castro grew as well.
Pancho Billa announced the team's third round pick at the 2018 NFL Draft, defensive tackle Harrison Phillips — which became the start of a bond between the two.
"Today there was just this kind of polar opposite feelings when I got the news. There's the grief, the sadness, the pain of losing someone I have such a strong relationship with. But also there's positives of the joy and happiness knowing he's in a better place," said Phillips.
He was on the field during training camp last summer, where owner Kim Pegula surprised Pancho with a hug.
Castro made trips this season for games in Minneapolis, Indianapolis, and Houston.
During a home game in late November, Pancho became the inaugural inductee into the Buffalo Fan Wall of Fame.
Castro's condition began to worsen over the last few months, entering hospice care at the end of April.
Still, the Bills once again included their superfan in the draft process, letting him call in the selection of defensive tackle Ed Oliver.
Oliver visited Castro in the hospital just about a week ago, leaving with a "Pancho Power" bracelet around his wrist.
Castro leaves behind his longtime partner Veronica, their son Ginobli and daughter Lourdes — and Bills Mafia, who he connected with unlike anyone else.
Ezra Castro was 39 years old.