The rivalry between Marvel and DC is heating up once again. After making a splash with his “Unite the Seven” poster for DC's "Batman vs. Superman: Dawn of Justice," Aquaman himself, Jason Momoa, is firing shots at comic-book movie house competitor Marvel.

According to CinemaBlend, Momoa was at last weekend's Indiana Comic Con to promote his role in the upcoming DC Comics crossover film. A fan asked the actor to sign his Aquaman poster and politely asked him why all of the DC movies are getting such hate. The actor killed two birds with one stone by answering the question with his autograph.

For those of you without sharp eyes, Momoa wrote “F--- Marvel” next to his signature, drawing criticism from die-hard Marvel fans. Still, odds are good that the former “Game of Thrones” actor, 35, was simply kidding around when he wrote the message.

This isn’t the first time that people in the movie industry have reignited the age-old supremacy debate between Marvel and DC.  Most recently, Kevin Tsujihara, the CEO of Warner Bros., which owns DC, claimed that the new movies from DC would be more “steeped in realism” and “edgier” than the ones Marvel has in the pipeline.

Prior to that, Marvel fired a shot in the form of Samuel L. Jackson, who plays Nick Fury in the Marvel Cinematic Universe (MCU). Speaking with MTV News, the actor said DC can’t seem to get people as excited for their superhero movies as Marvel can.

“I think Marvel has figured out a way to make those movies accessible to the public that DC hasn’t,” Jackson said. “I don’t know what that is. I don’t know why you can’t get Batman and Superman people as juiced up to be a part of that.” As Moviepilot points out, Marvel fired shots at DC previously, but in a much more subtle way.

The competition between the two giants will grow more intense in coming years. Starting in 2016, DC will roll out “Batman vs. Superman: Dawn of Justice,” “Suicide Squad” and “The Justice League.” These movies will appear somewhat concurrently with several from the MCU, which recently revealed a revised movie schedule stretching into 2019.