The Satanic Temple is suing the makers of TV series The Chilling Adventures of Sabrina for $50 million (£38m) over a statue.
Netflix and Warner Bros allegedly copied the group’s statue of the goat deity Baphomet in the programme.
Both production companies have declined to comment on the law suit.
Satanic Temple does not worship Satan, but instead seeks “to encourage benevolence and empathy among all people”.
Their lawsuit, filed on Thursday in New York, claims an icon similar to their own appears in four episodes of the series.
Lucien Greaves, co-founder of the Satanic Temple, posted a tweet comparing their statue with that in the show in October.
In an earlier post, Mr Greaves confirmed the group was going to take legal action against the production companies for “appropriating our copyright monument design to promote their asinine Satanic Panic fiction”.
Characters in the show who worship the “Dark Lord” or Satan practice cannibalism and forced worship, and the Satanic Temple argues its members are being associated with these “evil antagonists”.
Founded in 2012, the group does not believe in a supernatural Satan, but rather seeks to ensure the separation of church and state and holds Satan as a symbol of “opposition to arbitrary authority”.
The Satanic Temple created a statue of the goat deity Baphomet as part of its campaign to “complement and contrast” a Ten Commandments monument in Oklahoma City on the grounds of religious freedom.
Mr Greaves told US broadcaster CNBC that Baphomet has “come to represent us as a people” and that the statue in Sabrina “dilutes and denigrates” their group.