Chess Tactics Explained in English: Ward Farnsworth's Predator at the Chessboard. ChessOps - A Basic Chess Openings Guide. Wolf chess. Alfred Pfeiffer send me a copy of an old rule booklet, from 1943, describing this game.
The author, dr. Arno von Wilpert describes in this 16page booklet the rules of the game in German, French, Russian and English, and gives a problem and a sample game. He mentions that hundreds of games are played, and that prof. Joseph Boyer (well known for his propagation of chess variants) organised correspondence tournaments.