Oh, LEGO sets. An endless source of movie spoilers.

Seriously- in case you weren't aware, LEGO tends to market its big movie tie-in LEGO sets well before the movies themselves are in theaters- and often, those LEGO sets are based around potentially spoilery scenes in their respective films.

Case in point- LEGO just released a catalog containing their new "Avengers: Age of Ultron" sets. Which means we now know a number of scenes that will take place in the movie.

Movie Pilot found the catalog (although now the entire thing can be viewed at LEGO's official site), and they've found a number of spoilers hidden in those little LEGO bricks.

Ready to find out some "Age of Ultron" scoops? Here goes

For one, there's a LEGO set of the Hulk vs. Hulkbuster fight. That Hulk would fight Iron Man in his Hulkbuster suit, we already knew- but the set also includes an Ultron minifig, "Ultron Prime," and Scarlet Witch. As we know Scarlet Witch starts the film as a villain, could she be the one responsible for the fight? Maybe she's brainwashing one or more Avengers.

There's also a fight scene invoving Thor, Hawkeye and multiple Hydra members, and one where the Avengers assault a HYDRA stronghold in a castle, run by the evil Baron von Strucker, armed with Loki's staff from the first film.

The LEGO sets also show new Avenger the Vision, a one-on-one fight between Iron Man and Ultron, and one of Ultron's minions holding Loki's staff- all of which could be major spoilers.

This isn't the first time "Age of Ultron" LEGOs have crept online- two weeks ago, Comic Book Movie grabbed some shots of Iron Man's official LEGO helmet from the next film.

Check back soon for the latest news on "Avengers: Age of Ultron."