Big Mona is a giant catfish sought after by Snakebite Scruggs.
Big Mona is a huge catfish.
It seems to hate dogs.
Scooby-Doo On Zombie Island
While Scooby-Doo was on Jacques's boat, he saw the catfish, with Jacques pointing out that that must be Big Mona, who no one had been able to capture. Big Mona squirted water in Scooby's face and then splashed at him. Scooby retaliated by trying to get catch it, but lost his footing. Shaggy Rogers tried to help, but both still fell overboard, drawing the attention of two alligators.
Snakebite appeared in his boat and shoved his hook spear into one alligator, while the other bit the hook. He tussled with them a bit, allowing Scooby and Shaggy to climb onboard his boat. Shaggy thanked him, but Snakebite snarled that he should've left them to be eaten as their commotion scared away Big Mona. Snakebite's hunting pig, Mojo, then showed itself, snorting at Scooby. Snakebite claimed he was better than any hound dog, and could sniff Big Mona a mile away. The pig went to the side of the boat, just as Big Mona popped up, attempting to squirt Mojo, but getting Scooby instead.
By the end of the gang's stay, Snakebite and Mojo finally caught Big Mona, but a close by Scooby got stuck between on one of the dock's wooden pole and the ramp of the gang's boat. After struggling to get free, he flew into the air and into Big Mona's net, sending it back into the river.
- DTV1. Scooby-Doo On Zombie Island (no lines)