The Wel's Catfish. Yeah, it's big.
With those enlongated and specialised fins of theirs, they whip up an eddy to disorient their prey- they then gobble the prey with their super-wide mouth. They live in lakes and slow-moving rivers in Europe and parts of Asia.
One of the largest ones on record is 8 feet, 2 inches. It weighed just shy of 200 pounds. There have been larger catches, but I don't know the length/weight of those. >: You can eat them when they're under 15lbs, but other than that, the fatty tissue is... really fat. And the eggs are poisonous.
They've never been documented to attack people, but the Goliath Grouper has:
They've also been referred to the Jewfish, and they're really agressive and won't think twice about attacking/attempting to eat a scuba diver swimming near their home. They grow to about 8.2 feet and can weight 800lbs. They're delicious.