Hello, here is a small list of breakfast that are/can be under 100 calories!
~ Smoothies (calories depend on what you add)
~ Crepés
~ Pancakes ( 70cal per pancake)
~ Yogurt with fruits
 ~ A small fruit salad
~ Oatmeal (made with water)
~ Protein bread with cottage cheese and cucumber
~ Rice cakes with toppings (like cheese, jam, …)
Those are a few that I could think of right now! I hope I could help you with it and hope you have a great day/night! ♥