Foxfish

A foxfish is like the nightmare that your pet chickens and your neighborhood rabbits hope they never see. The foxfish comes out at night and goes into you chicken enclosure or rabbit burrows and then kills all of them one by one. They grow up to 50 feet and even sometimes attack small children.
How To Avoid It
Siamese Fighter Fish are the only know fish that can kill them due to their sick as karate skills. So always have one of them nearby