Herman Munster is the nominal head of the Munster family in The Munsters, a short-lived 1960s supernatural comedy that later became a cult hit in syndicated reruns alongside The Addams Family. Much of the series humor came from the contrast between the family's well-meaning nature and their cheerfully macabre lifestyle and horrific appearance (based upon Universal Studio's iconic black-and-white monster films of the 1940s and 1950s); for example, "Grandpa" Munster often played checkers with invisible ghosts, while son Eddie's pet was a firebreathing dragon that lived under the staircase, and one of their visiting relatives turned out to be The Creature from The Black Lagoon. Further humor came from the contrast between Herman's superhuman strength and his childlike nature in which he constantly underestimated his own strength.
Played by popular television comic actor Fred Gwynne, Herman Munster is a well-meaning man-child, with childish gullibility, naivete, and a lack of emotional self-control, occasionally responding to a particularly unfair experience by jumping up and down in a comic temper tantrum while pouting "Darn! Darn! Darn!" Despite all this, he manages to be a loving husband to wife Lily, the vampire daughter of Count Dracula, and a good influence on his son Eddie, a young werewolf, and on his niece Marilyn, a beautiful young woman considered ugly by the rest of the family and who, despite her ordinary human appearance, shares the family's supernatural invulnerability.
The Munsters all share a supernatural invulnerabilty, happily making meals of substances that would kill an ordinary human being and taking no damage from things that would wound an ordinary person, such as electrocution, being blown up, and drinking furiously boiling liquids. The adults of the family -- Herman Munster, Lily Dracula-Munster, and "Grandpa" a.k.a. Count Sam Dracula -- all appear to be immortal, and both Herman and Lily have demonstrated superhuman strength a number of times.
Backstory: Built by Dr. Frankenstein, Herman wandered away until he was adopted by the Munsters clan, an eccentric British noble family perfectly comfortable with the uncanny and the supernatural. Herman eventually met and married Lily Dracula, daughter of the famous Count Dracula of Transylvania, and later had a son, Eddie. Looking for a better life, Herman and Lily emigrated along with "Grandpa" (Count Dracula), their werewolf son Eddie, and their beautiful niece Marilyn to the United States, where they try to fit into their new American culture while continuing to honor the ways of the Old Country.
Note: There have been a number of efforts to update (and exploit) the original Munsters series, including two films with the original cast, several uninspired TV-movies with a new cast, an odiously tepid sequel TV series plagued by "very special episode" moralizing, and a recent effort to revise the family as cheap knock-offs of The Addams family.