Pre-heat the oven to 350°F.
Wash and slice squash into small medallions or, if the squash is large, dice into smaller pieces.
Put squash into a large mixing bowl.
In a separate bowl, mix together the soup, mayonnaise, eggs, cheese, onions, salt and pepper.
Pour over squash; stir until well mixed.
Pour into an ovenproof casserole dish.
Crush crackers while in "sleeves" or place in a resealable plastic bag prior to crushing.
Pour crushed crackers into a bowl.
Melt butter in the microwave and stir into crackers until moist.
Drizzle on top of casserole.
Feel free to make more or less of the topping; more topping = more yummy.
Place in the pre-heated oven and bake until bubbly and brown on top; 45 to 50 minutes); bake for 30 minutes covered with foil to help prevent crackers from burning; remove foil and continue to bake for 15 to 20 minutes longer.