Preheat the oven to 400 degrees and spray or grease a casserole dish.
Add the shredded rotisserie chicken, cottage cheese, buffalo sauce, and seasonings to a large mixing bowl. Stir until everything is evenly combined.
Spread the buffalo chicken mixture evenly into the prepared casserole dish.
Sprinkle the shredded cheddar cheese evenly over the top.
Arrange the frozen tater tots in an even layer on top of the casserole.
Bake uncovered for 40–45 minutes, or until the casserole is hot and bubbly and the tater tots are crispy and golden brown.
Top with sliced green onions before serving. Optional: drizzle with ranch or extra buffalo sauce.