The director's comments came in response to Donald Trump's physical test results, which were just revealed. President Trump was listed at 6 feet 3 inches tall and weighing 108 kgs (239 pounds) in the test report by White House doctor, Navy Rear Admiral Dr Ronny Jackson.
"Come to think of it, perhaps Trump doesn't weigh as much as one would think because his tiny hands weigh a gram a piece," James Gunn posted on Twitter.
"I will give $100 thousand dollars to Trump's favourite charity if he will step on an accurate scale with an impartial medical professional, okayed by both of us. For real," Mr Gunn added.
"Trump's medical exam says he's 6'3" and 239 pounds. Albert Pujols is 6'3" and 240 pounds. If the dementia tests are equally accurate, we are doomed," Mr Gunn tweeted.
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