Last night, Earth's mightiest heroes hit the town — and by town, we mean Los Angeles, for the red carpet premiere of "Avengers: Age of Ultron."

It wasn't just the heroes and villains of the new "Avengers" movie who strutted their beautiful selves all over the carpet, either. There were some surprise guests from the Marvel family in attendance as well, plus at least one or two familiar but unexpected faces.

Check out our round-up of the best photos of the night — including Robert Downey Jr.'s incredible Instagram debut!

Captain America wants YOU...

...to talk to the hand.

Such a sassy super soldier.

Anthony Mackie, looking fly.

No such thing as too much Falcon.

Robert Downey Jr. attempts a Spider-Man pose.

Stick to the iron suit of armor, buddy.

Don Cheadle with his new ride.

It's no War Machine armor, but it'll do.

Stan Lee makes a cameo!

Wouldn't be a Marvel night without Stan the man.

Joss Whedon is still awake.

How he's not just sleeping forever after making "Age of Ultron," we will never know.

Ah! Nathan Fillion!

What's he doing at a Marvel premiere? Start the "Nathan Fillion is Black Bolt" rumors now!

The Hulk meets Falcon.

And suddenly we want this crossover movie more than anything on the Phase Three lineup.

Bruce Banner loves selfies.

But no selfie stick. Selfie sticks make him angry, and you wouldn't like him when he's angry.

Thor also loves selfies.

"ANOTHER!"

Scarlet Witch and Ultron conspire.

Look how cute they are, as they plot your demise.

Black Widow has a new 'do.

What do you think of Natasha's new undercover look?

Widow and friends.

Seriously, Scarlett Johansson, you are doing this right.

The Hulk makes a friend.

Mark Ruffalo, Earth's nicest hero?

Hawkeye meets Melinda May.

And now we need this "Avengers" and "Agents of S.H.I.E.L.D." crossover episode immediately.

The Hulk challenges Captain America.

Steve Rogers, playing it cool in the face of the Jade Giant completely breaking his arm.

Aaron Taylor-Johnson and Sam Taylor-Johnson strike a pose.

Fifty shades of hotness.

Here's Paul Bettany looking like a ... wait for it...

...good-looking man. What, were you expecting a different punchline?

Lindsay Weir?

Lindsay Weir.

Jared?

Jared.

Chris Hemsworth admires himself.

Can't say we blame him.

Jon Favreau looks Happy!

Never forget the man behind the "Iron Man."

Hulk takes a call.

"You said 30 minutes or less," he growled at the pizza delivery service before Hulking out all over the red carpet.

Full Hulk mode!

This is what happens when you make Mark Ruffalo angry. He turns into Lou Ferrigno.

Mock. Yeah! Ing. Yeah! Bird. Yeah!

Yeah. Yeah!

Thor signs autographs.

His signature is a lightning bolt.

Oh, hey! It's Ant-Man!

...or is it?

Paul Rudd, mid-Celery Man moves.

Chadwick Boseman, looking like a true hero.

He's gearing up for his Black Panther debut.

Hawkeye sees something!

Earth's mightiest sniper, always on high alert.

Scarlet Witch strikes a pose.

Elizabeth Olsen's mind-bending hero dominates the red carpet.

Paging Maria Hill...

...and paging her boss, Nick Fury!

Epic Samuel L. Jackson beard is epic.

Do you Yondu?

Michael Rooker do.

Ultron wins.

He's wielding Mjolnir, after all. We're not worthy.

Behold, Robert Downey Jr.'s first ever Instagram!

The gang gathers with Jimmy Kimmel.

"HEMSWORTH."

RDJ's second Instagram, an up-close and personal look at Thor.

The Avengers assemble...

...on stage, in a video captured by RDJ's new Instagram. And that's the ball game!