The lawsuit has been filed on behalf of the family of the deceased and other farmers in the area after an animal rights group labelled the cattle farmer a "slave holder", reported the Süddeutsche Zeitung.
Helmut Dresbach, who filed the lawsuit on behalf of the Oderberg Farmers' Association and the family last week in Cologne, said that using the image of a deceased man for political reasons was distasteful.
On January 8, the 18-year-old son walked into the cow barn to find his father's lifeless body. According to the police report, while the farmer was repairing a stall door, the stall's occupant, the family's bull, gored him to death.
According to Dresbach, the farmer was the owner of a small dairy farm with 70 cows and the one bull. All the animals had large grazing spaces and were fed "the best grass" at their home.
Shortly after the dairy farmer's death, an image of the deceased appeared on the Facebook page of Animal Peace, an animal rights organisation founded in the 1980s. In the posting, Animal Peace celebrated the bull's actions.
"Near Cologne, a three-year-old bull has attacked and fatally wounded his slave holders. We bow to this hero of freedom. We hope many more cattle follow him in the uprising of the downtrodden."
The post is still on the Facebook page.
Silke Ruthenberg, the woman who made the post to her 5,000-strong Facebook group, said she doesn't regret her actions.
"If I get a few more vegans away from zucchini and spaghetti recipes and into the actual political issues, then its my pleasure to have another day in court," she told the Munich-based newspaper.
Already, the post has received criticism from fellow animal rights activist groups.
"The death of a person cannot be used for the rights of animals," said a PETA spokesperson.
"Whoever does that kind of thing does not belong to serious animal protectors and only does massive damage to animal rights groups," said a spokesperson from the German Animal Rights Federation.
The North Rhine-Westphalia courts in Cologne are scheduled to hear the case next week on Tuesday.