As the oldest living being in Fantasia, The Childlike Empress (The Neverending Story) has a lifespan that is not measured by time, but by names. Each new name grants her a new life.
Black Sperm (One-Punch Man) has 11,449,001,712,554 lives.
Darkonda (Power Rangers in Space) has nine lives.
Solomon Grundy (DC Comics) Born on a Monday, Christened on Tuesday, Married on Wednesday, Took ill on Thursday, Grew worse on Friday, Died on Saturday, Buried on Sunday, That was the end, Of Solomon Grundy.
Like his namesake, Wildcat (DC Comics) has 9 extra lives after being cursed.
Kenny (South Park) is famous for dying in almost every episode in the first five seasons of South Park
Raava (Avatar: The Last Airbender & Avatar: The Legend of Korra)
Avatars (Avatar: The Last Airbender & Avatar: The Legend of Korra)