There are 4 hormones that are counter-regulatory to insulin, i.e. they are upregulated during hypoglycemia to increase blood sugar:
3. Glucocorticoids (cortisol)
4. Growth hormone
Glucagon and epinephrine both cause an increase in glycogenolysis; the main difference is that glucagon acts in the liver, whereas epinephrine acts in muscles, fat, liver, and kidneys.
Glucocorticoids are interesting...they cause gluconeogenesis in fat and muscles, but cause glycogenesis in the liver (Kaplan explains that maybe the reason for the opposite actions is that it makes glucose in fat and muscles, which can then be used to increase glycogen storage in the liver...I find that really weird!)