Avengers: Infinity War's funniest line was improvised by Dave Bautista

*WARNING: MAJOR SPOILERS FOR AVENGERS: INFINITY WAR*

It's the line that birthed a thousand memes.

The Guardians of the Galaxy arrive at Thanos' crash-landed ship only to discover Iron Man, Doctor Strange, and Spider-Man. Assuming they're minions of Thanos, we're treated to a brief inter-hero brawl, before everyone starts tense negotiations.

"Where's Gamora?" Peter Quill (Chris Pratt) demands, to which Tony Stark (Robert Downey Jr.) replies: "I'll do you even better: who is Gamora?"

Drax then cuts in with the punchline: "I'll do you one better: why is Gamora?" A line that, as screenwriters Christopher Markus and Stephen McFeely revealed to Yahoo, wasn't in the original script.

“The script only said, ‘Where is Gamora?’ ‘I’ll do you even better: Who is Gamora?’ And then one day Bautista just goes, ‘I’ll do you one better: Why is Gamora?’” Markus said. “It’s like, ‘OK, you’re very good at your job.’” And the rest is history.

Joe Russo also revealed at a Q&A at the University of Iowa that Tom Holland ad-libbed his death scene (via Digital Spy), including the moment he turns to Tony and says: "I don't want to go."

Avengers: Infinity War is out now.

Follow Independent Culture on Facebook for all the latest on Film, TV, Music, and more.