Joker (The Dark Knight) - Wikipedia

The Dark Knight's Joker Is the Most Dangerous Version of the Character

Joker (character) - Wikipedia

Wikipedia infobox for the Batman, in a TL where Batman existed : r/AlternateHistory

The Dark Knight Rises - Wikipedia

The Dark Knight Rises (soundtrack) - Wikipedia

Batman: The Long Halloween - Wikipedia

In the dark knight (2008) the old man being compared to the joker's father is actually senator Patrick Leahy. Senator Leahy has appeared in 5 Batman movies and even voiced a senator

Heath Ledger, Joker, Brokeback Mountain, 10 Things I Hate About You

Batman: Haunted Knight - Wikipedia

Joker (character) - Wikipedia

1 Genius Detail Proves Joker's The Dark Knight Plan Began In Batman Begins