If there's one thing that actor Mark Ruffalo is known for, it's for his portrayal as everyone's favourite big green Avenger, The Incredible Hulk. But if there's another thing he is known for (aside from the many other critically acclaimed movies he has starred in), it's for his tendency to reveal spoilers, much to the dismay of the movie's directors.

And with the recent release of the full-length Avengers: Endgame trailer, Marvel fans are now gearing up for the franchise's climactic blockbuster.

And to add to the fans' excitement, none other than the Incredible Hulk made an appearance on The Tonight Show Starring Jimmy Fallon to promote the highly-anticipated superhero flick.

But considering Ruffalo's tendency to slip up in interviews and reveal spoilers, Fallon decided to test out his new "lie detector" by asking the actor a few questions. The test started out pretty tame - with questions such as, "What's your name?" Which Ruffalo, of course, answers correctly as indicated by the lie detector.

The test escalates ever-so-slightly when Fallon asks the 51-year-old actor if he is "currently dressed like a tiny leprechaun?" But as ever, Ruffalo, responding "no", answers correctly proving that the lie detector is, in fact, reliable.

Fallon then starts on the questions that fans actually want answers to - questions on the Avengers: Endgame.

The host asks Ruffalo: "Is the Hulk a shapeshifting alien known as a Skrull?" Ruffalo replies that he cannot answer the question.

Then Fallon asks him: "Are there any hidden clues in the latest Avengers trailer that no-one has figured out yet?" and the lie detector responds accordingly.

In fact, it's safe to say that, judging from the lie detector's responses, there was very little Ruffalo could keep hidden from The Tonight Show host.

You may remember that in October, Ruffalo's appearance on Fallon's show led to him getting "fired" after revealing a few too many spoilers. This was announced, in jest, by the Russo brothers on their official Twitter page:

If there's one thing that actor Mark Ruffalo is known for, it's for his portrayal as everyone's favourite big green Avenger, The Incredible Hulk. But if there's another thing he is known for (aside from the many other critically acclaimed movies he has starred in), it's for his tendency to reveal spoilers, much to the dismay of the movie's directors.

And with the recent release of the full-length Avengers: Endgame trailer, Marvel fans are now gearing up for the franchise's climactic blockbuster.

And to add to the fans' excitement, none other than the Incredible Hulk made an appearance on The Tonight Show Starring Jimmy Fallon to promote the highly-anticipated superhero flick.

But considering Ruffalo's tendency to slip up in interviews and reveal spoilers, Fallon decided to test out his new "lie detector" by asking the actor a few questions. The test started out pretty tame - with questions such as, "What's your name?" Which Ruffalo, of course, answers correctly as indicated by the lie detector.

The test escalates ever-so-slightly when Fallon asks the 51-year-old actor if he is "currently dressed like a tiny leprechaun?" But as ever, Ruffalo, responding "no", answers correctly proving that the lie detector is, in fact, reliable.

Fallon then starts on the questions that fans actually want answers to - questions on the Avengers: Endgame.

The host asks Ruffalo: "Is the Hulk a shapeshifting alien known as a Skrull?" Ruffalo replies that he cannot answer the question.

Then Fallon asks him: "Are there any hidden clues in the latest Avengers trailer that no-one has figured out yet?" and the lie detector responds accordingly.

In fact, it's safe to say that, judging from the lie detector's responses, there was very little Ruffalo could keep hidden from The Tonight Show host.

You may remember that in October, Ruffalo's appearance on Fallon's show led to him getting "fired" after revealing a few too many spoilers. This was announced, in jest, by the Russo brothers on their official Twitter page: