Catfish - can grow HUGE and try to eat the player

I think they should add Catfish to the game.  In the US these fish can be found in lakes, rivers, streams etc.  They are very common in rivers like the Mississippi, where they can grow to enormous sizes. Divers in the Mississippi have reported seeing Catfish that are as big as a human or larger. (This may be exaggerated but it could be fun in the game.)  They have also reported these fish will try to eat anything that swims too close, including the divers. As they get bigger and bigger these fish become less mobile and will eventually find a hole or a cave and just sit and wait for unsuspecting victims to swim by.  How cool would it be to have a mob that gets bigger and bigger as time goes on in the game?