The
Clarias Batrachus, (The albino version sold as "Albino Clarias Catfish") also was called a
Walking Catfish. It can grow (quickl;y) to 22 inches, and will likely
eat all its tankmates that fit into its mouth. It's not legal to sell here in New York, & probably many other states as well.
Perhaps they are best known for their ability to use atmospheric air while crossing marshy areas, hunting for food, or just surviving in very poorly oxygenated waters.
It might be an "Urban Legend"( but I happen to believe that this happened ) that hundreds of these catfish after escaping from fish farm ponds in Florida, & traveliing across land came across RR tracks and as they were dying,attempting to cross the tracks were piling up to such an extant that they were causing trains to De-Rail!
This link might help you answer any other questions you might have.
http://www.aquariacentral.com/fishin.../clarias.shtml