Does the Joker know he's in a comic?

Well, it's ambiguous. In some interpretations, Joker might be oblivious to being in a comic world. But in others, there are hints that he might have some awareness, though it's not clear-cut.

I think he doesn't. The Joker's character is often depicted as being so immersed in his chaotic world that he probably doesn't have that kind of self-awareness.

I don't think he's fully aware. The comic's world is so immersive for him that he might not question its nature.

Well, sometimes it seems like he does. He often breaks the fourth wall and makes comments that suggest he's aware of his fictional status.

Sure, Deadpool frequently acknowledges being in a comic. This awareness is a defining trait that adds to his humor and unconventional nature. It allows for meta-commentary and breaks the fourth wall.

It's hard to say for sure. Maybe he does, maybe he doesn't. The comic creators haven't made it clear.

Well, it's often through his awareness of the fourth wall. He sometimes makes comments or actions that suggest he knows he's in a fictional world.

Hard to say for sure. Maybe he does, maybe he doesn't. It all depends on how the story unfolds.

In most versions, Joker doesn't seem to have that awareness. His focus is on causing mayhem and chaos without considering the meta aspect of being in a comic book. It's part of what makes his character so wild and unhinged.

Yes, Deadpool is aware that he's in a comic book. He often breaks the fourth wall and makes references to it.