The FF return home from an extra-dimensional adventure to find the Baxter Building and everyone in it just a little bit off. Their usually-angry neighbors are suddenly all too happy to chat. They come bearing strange gifts, and oddly enough, seem extremely interested in the FF's powers. Soon it becomes obvious that the Baxter Building has been invaded by shape-shifting aliens - THE SKRULLS! But as the FF discover, whenever you deal with Skrulls, there's always more going on than meets the eye!

The Fantastic Four face the metallic menace of Doctor Doom!

When Reed is accused of having purposefully exposed Susan, Johnny and Ben to the cosmic rays that transformed them into the Fantastic Four, the team is torn apart. But as Susan, Johnny and Ben individually wonder if Reed is capable of such a betrayal, they're attacked by the mastermind behind the plot against Reed � Doctor Doom! Now the team has to escape Doom's prisons in order to save Reed and prevent Doom from plunging the city into the Negative Zone.

When an old friend of Reed's shows up looking for help, the Fantastic Four are in for the fight of their lives! His name is Bruce Banner, and he has a terrible secret � he's the Incredible Hulk. And when Banner Hulks out and goes on a rampage through New York City, it's up to the FF to stop him. Can they protect New York from the Hulk? Can they protect the Hulk from the group that's hunting him? Most important of all, has Ben Grimm finally met his match?

Susan forces the rest of the team to take part in 'Fantastic Fifth for a Day,' an attempt to drum up a little good PR for the team. But the contest is interrupted by the return of the SKRULLS. The FF aren't exactly worried by the awkward shape shifting aliens� that is, until they reveal the SUPER SKRULL�a genetically altered warrior who possesses all of the Fantastic Four's powers! And the team realizes they're in real trouble when they learn the Super Skrull has teamed up with Ronan the Accuser! The team's only hope might lie in the hands of the 'Fantastic Fifth�' a nerdy teenager named Rupert.

One of Reed's experiments goes awry, causing the Fantastic Four to begin shrinking� and they're not stopping. Within hours, the FF will shrink out of existence unless Reed can reverse the effect. But at miniature size, even a trip to the lab becomes a challenge, even more so when HERBIE's security systems recognize the action figure sized FF as an infestation of rodents and begins to hunt them down! Even with a helping hand from the Astonishing Ant-Man, the FF are in for a giant-sized challenge.

The FANTASTIC FOUR fall into a trap and are taken to the NEGATIVE ZONE, where they're attacked by ANNIHILUS and his warriors. But all is not as it seems - something in the Zone is affecting the Four's powers. Things go from bad to worse when DOCTOR DOOM arrives, apparently in league with Annihilus! But Doom isn't one to share power, and he takes Annihilus' energy source back to Earth with him. But even if the Four can escape Annihilus, how can they defeat Doom, who now has the power to destroy the world?

The deviant monster GIGANTO bursts up from the underground, putting a quick stop to the Fantastic Four's day off. Now it's up to them to stop the monster from destroying the city, but the FF quickly realize that the giant monster has a specific target� the BAXTER BUILDING! The mystery of the monster's appearance will lead the FF deeper into Subterranea than they've ever gone, and right into a TRAP. The MOLE MAN sent Giganto to attack the FF, but has a grander scheme in the works. Because the only thing better than having Giganto destroy the FF is to control an ARMY of Gigantos.

The Fantastic Four are evicted from the Baxter Building! The sinister Puppet Master has managed to turn the entire city against the FF from inside his prison cell, and it's up to them to clear their good names. What's more, they must stop Puppet Master from completing his ultimate goal—to control the mind of every person on the planet!

When Johnny gives an unauthorized tour of Reed's lab to his friend Frankie, things go bad� real bad. Frankie is sucked into another dimension, and Johnny goes in after her to try and keep anyone from finding out! But what he didn't realize is that something came OUT of the dimensional portal as he went in: a harmless little bug. Now Johnny and Frankie are trapped and on the run while Reed, Ben and Susan are left to deal with that little bug. Which is growing. And multiplying. And eating its way through the Baxter Building.

Susan and Johnny witness the arrival of Namor, the Sub-Mariner, who bans humankind from using the oceans of the world. Susan takes Johnny (who hates the water with a passion) under the sea, hoping to reason with Namor. Instead, the siblings become prisoners of Namor in the fabled city of Atlantis. Reed and Ben fight their way through a swath of undersea monsters to come to their rescue, but Namor proves to be a formidable foe. And even worse, impressed by Susan's eloquent pleas for peace, he decides to keep her in Atlantis as an ambassador.

When a cosmic-ray saturated piece of the Fantastic Four's space station falls to earth on the Jersey Shore, the clay of eccentric local sculptor Phillip Masters, becomes energized with the power to control the minds and actions of others. The sculptor becomes THE PUPPET MASTER and uses miniature clay versions of the Fantastic Four to control the real heroes. Puppet Master captures award-winning New York artists, including his own step-daughter, Alicia, in an attempt to take over his "rightful place" in the art world.

Reed summons one of his deep space probes back to the Baxter Building for repairs, only to find that someone has hitched a ride on it back to Earth: the Impossible Man! The small, impish alien seems harmless enough, but the Fantastic Four soon realize that this creature, who can turn into anything, has turned into a big problem for them! Now they have to figure out how to get the Impossible Man off the planet before he goes from 'annoying' to 'dangerous!'

While Reed conducts an experiment designed to cure Ben Grimm, there's an energy disruption which causes the experiment to go haywire! Now the Fantastic Four's powers have switched, but they don't have time to get used to them before they have to save the city. Because the energy disruption that caused the accident was the work of Doctor Doom, and now the FF, new powers and all, have to stop Doom before he destroys the city with his scheme.

The Fantastic Four make their "Marvel Mash-Up" debut in the newest episode, as seen Sunday mornings inside Marvel Universe on Disney XD!

The Fantastic Four travel around the world fighting lions and hipsters in the latest "Marvel Mash-Up"!

Doctor Doom pays a visit to the Fantastic Four in another hilarious "Marvel Mash-Up"!

The Frightful Four can't decide who will get to destroy the Fantastic Four in the latest "Marvel Mash-Up," as seen Sunday mornings inside Marvel Universe on Disney XD!

Magneto proves why he's the Master of Magnetism in a new "Marvel Mash-Up" featuring the Fantastic Four!

Doctor Doom displays his musical talents in a new "Marvel Mash-Up" featuring the Fantastic Four!

The Invisible Woman & Mr. Fantastic just can't seem to get along in another "Marvel Mash-Up" starring the Fantastic Four!