Even people who don't follow baseball would likely recognize the mascot of Philadelphia's baseball team. The Phillie Phanatic—a furry, green, bird-like creature who's been entertaining Phillies fans for decades—consistently ranks among the most popular mascots in the MLB. Now, NPR reports that the Philadelphia Phillies have filed a lawsuit against the character's creators to stop the Phanatic from becoming a free agent.

In the 1970s, the mascots for the Phillies were the fairly forgettable 18th-century siblings Philadelphia Phil and Philadelphia Phyllis. Looking for a change, the baseball team commissioned the New York design firm Harrison and Erickson—whose previous credits included Muppets and the Montreal Expos' Youppi!—to craft a new character to personify Phillies fans. The energetic, passionate, frequently misbehaved Phillie Phantic debuted at Veterans Stadium in April 1978.

More than 40 years later, creators Wayde Harrison and Bonnie Erickson (the puppet designer behind Miss Piggy and Statler and Waldorf) are threatening to make the Phanatic a free agent that cheers for teams other than the Phillies, according to a lawsuit filed by the Philadelphia baseball team. The team claims it paid the design firm $200,000 by the end of 1980, and that a separate licensing deal was struck in 1984 when terms were renegotiated for $215,000. That 1984 agreement, the lawsuit alleges, gave the Phillies the rights to the Phillie Phanatic in perpetuity.

Harrison and Erickson allegedly disagree. According to the lawsuit, the creators sent the Phillies a notice saying they would forbid the team from using the Phanatic's likeness past June 15, 2020 unless a new licensing deal was agreed upon. They also apparently threatened to shop the mascot around to other teams.

This isn't the first time the Phillie Phanatic has been involved in legal trouble. In 2010, the Phanatic was working a private gig when he decided to surprise a woman by tossing her into a pool. She sued, targeting several men known to wear the costume at the time because she didn't know who had been behind the mask.

[h/t NPR]