Who are the anti-creatures and what is it that they want? Who they are is difficult to answer. They could be anyone, your neighbour, your best friend, maybe even a politician. Their motives are about as varied as their identities. There are some of them who hate creatures with all their being, who just want them all dead. Others think they've simply become too strong for the Ministry to handle and think they have to take action into their own hands. Others are simply terrified of the destruction creatures can cause.
The most notable act that the anti-creatures have done is the Gringotts Massacre. On the 30th of December, 2057, a masked group of wizards and witches stormed the Wizarding bank. All the goblins inside were murdered. The people responsible for it have remained elusive to the Ministry to this day.
A number of notable stores have begun to ban creatures from their establishments. These places include The Hog's Head Inn in Hogsmeade, Dostoevskogo in Port Durmstrang, Le Verre Dore in Palaisvue, and the Hissing Snake in the magical city of Azorat.
There are anti-creatures everywhere, but perhaps nowhere in quite as many numbers of the Sons of Galen. Though the organization began as a cult dedicated to immortality, in recent years their ranks have begun to turn away from that cause towards eliminating creatures. However, there are still members loyal to their original mandate.