The original lineup of Ani-Men ( Ape-Man, Bird-Man, Cat-Man, Frog-Man) were recruited by a man named Abner Jonas under the guise of the Organizer. Abner Jonas was a candidate for mayor of New York City, who sends the Ani-Men on missions to undermine the current administration. Daredevil defeated both the Ani-Men and their leader and sent them all to prison.
Later, Ape-Man, Bird-Man, and Cat-Man formed a team refered to as the Unholy Three and worked with the Exterminator (who eventually becomes the Death-Stalker and Count Nefaria). The Ani-Men served as henchmen to the count and have come at odds with various heroes. They would go on to under-go a treatment by Count's scientist to become more animal like.
A new band of Ani-Men has risen. These are created by the High Evolutinary and are his servants.
The Ani-Men were created by Wally Wood in 1965 and first appeared in Daredevil #10.