Thaw fish, if frozen. Grease a 15x10x1-inch baking pan; set aside. Rinse fish; pat dry with paper towels. Bias-cut fish into 1-inch-wide strips. Cut the zucchini in half crosswise; cut each half lengthwise into 6 wedges.
Preheat oven to 425 degree F. Place the cornflakes in a large resealable plastic bag; seal bag. Crush cornflakes slightly; set aside. In a large bowl combine the ranch dressing and hot pepper sauce. Set aside half of the dressing mixture to use as a dipping sauce. Add catfish and zucchini strips to remaining dressing mixture in bowl; stir gently to coat.
Add one-third of the zucchini and one-third of the fish to the bag with the crushed cornflakes. Seal and shake to coat. Remove zucchini and fish; place in a single layer in prepared baking pan. Repeat with remaining zucchini and fish.