The National Football League of 2019 might be nearly unrecognizable to those who founded it a 100 years ago. Today’s NFL is a slick and sophisticated money-making machine that has become the pre-eminent sports league in the United States, a stark contrast to the unsparing, smash-mouth sport of a century ago. As part of the league’s relentless marketing efforts and community outreach, NFL teams use mascots to connect with their fan bases.

To find out the story behind each NFL mascot, 24/7 Tempo reviewed media sources such as ESPN, as well as the Pro Football Hall of Fame and the websites of NFL teams. All but four NFL teams — Green Bay Packers, New York Jets, New York Giants, and Washington Redskins — have mascots representing their teams.

Unlike college mascots, which have a longer and deeper connection with the universities they represent, most NFL mascots came on the scene within the last 25 years. Some mascots were adopted by teams after NFL Properties, the merchandising and licensing arm of the National Football League, developed characters as part of the Team NFL Heroes league-wide mascot program in the mid-1990s.

Mascots are used by teams to cultivate community relations and connect with younger fans, all efforts to avoid depleting their fan bases. These are the sports teams running out of fans.

Mascots are also a revenue source and can be booked for birthday parties and other events on a team’s website. Many mascots have developed their personas through their own Facebook pages and Twitter handles.

NFL mascots can be lovable or annoying, exuberant or aloof, shaggy-maned or jut-jawed. Some teams such as the Saints have more than one. Not all mascot launches have been successful. The Vikings had several misfires before settling on a comically hulking caricature named Viktor who has resonated with fans.

Some mascots have run afoul of the league and owners of other teams because of over-exuberant behavior on the field. Jaxson de Ville, the mascot of the Jacksonville Jaguars, drew the ire of Indianapolis Colts President Bill Polian in 2007 over his on-field antics. The Carolina Panthers mascot overstepped a boundary in 1996 when during a game between the Panthers and Pittsburgh Steelers he fell on a live ball following a punt. Mascot misconduct can stoke team rivalries. Here are the biggest rivalries in sports.

Click here to see the story behind every NFL mascot.