The croissants will make to about a third of the battle box and then return the same path.
The Donuts do not follow the lines of the web and bounce around the box. Two spiders means that the amount of spiders will be larger. It will either show a spider, two spiders, a Donut or a Croissant (boomerang).
Muffet's first attack is to turn your heart purple.Here are some pointers for the Muffet fight if you need to wait her out. If you have to SPARE Muffet manually (because you couldn't afford the Donut or the Cider), you need to wait long enough (17 turns) until Muffet receives a telegram from the spiders in the Ruins who will explain that you are not evil to spiders. The first can be found in the Ruins and is the cheaper of the two, with the Donut only costing 7G and the Cider 18G. If you buy an item from either of the two Spider Bake sales (Spider Donut or the Spider Cider) and use it in battle, Muffet can be SPAREd instantly without having to fight her.