Groot originally appeared as an invader that intended to capture humans for experimentation, but was later reintroduced as a member of the Guardians of the Galaxy.

When billionaire Simon Stagg sent adventurer Rex Mason to Egypt to retrieve the priceless Orb of Ra from a pyramid, he never expected him to return. Stagg's henchman, Java, attacked Mason, leaving him for dead. But Rex fell into a hidden chamber and was exposed to the Orb, whose radiation changed Mason into the freakish shape-shifting element man Metamorpho.

Coming from a long, proud line of warrior kings, T'Challa, king of Wakanda, champions the cause of his people both as their ruler and as the sleek superhero known as the Black Panther.

The Baxter Building is a fictitious 35-story Manhattan office building that served as the Fantastic Four's original headquarters. The landlord, Walter Collins, was initially eager to rent to a superhero team for the publicity and prestige, but soon regretted his decision as the building became a constant target for supervillains beginning with Fantastic Four #6 in which Doctor Doom launched the entire building into outer space.

Skaar is the son of Hulk and of Caiera the Oldstrong, who conceived Skaar during the Hulk's time on Caiera's home planet, Sakaar.

Ummm ... Doctor Strange is a Marvel hero. Duh.

Green Lantern originally appeared in All-American Comics #16 (July 1940), published by All-American Publications, one of three companies that would eventually merge to form DC Comics. This Green Lantern's real name was Alan Scott, a railroad engineer who, after a railway crash, came into possession of a magic lantern which spoke to him and said it would bring power.

Mary Jane Watson, Spider-Man's main love interest and later his wife, takes a job at Stark Industries after Iron Man and Doctor Doom destroy her nightclub trying to subdue Madame Masque. Tony offers her the job both as an apology and out of his need for a competent personal assistant.

The Scarlet Witch (Wanda Maximoff) and her twin brother Quicksilver (Pietro Maximoff), the children of Magneto, were born without their father's knowledge in the mountains of Eastern Europe. Once manipulated by Magneto into serving the cause of terrorism, they now dedicate their lives to fighting crime.

Although The Brave and the Bold started out as an anthology series featuring characters such as Robin Hood and the Viking Prince, beginning with issue #59 it became a team-up title featuring Batman and a different hero each month.