Aga saga is a common term used to describe a lengthy story that might be exaggerated or melodramatic. There are several synonyms that you can use to replace this phrase and add variety to your writing. One such synonym is "tall tale," which refers to a story that is not completely true. Another term you can use is "yarn," which implies a tale that is spun or fabricated. "Fable" also fits the bill as a synonym for Aga saga as it refers to a story that teaches a moral lesson. Other possible synonyms include "legend," "myth," and "epic." Overall, these and other synonyms can help add a colorful touch when you want to describe a dramatic and exaggerated tale.