Cannonball: Baron Munchausen voluntarily sits on the cannonball, accepting external truths or principles as self-evidently valid. He lets these truths propel him on a path, requiring no further justification.
Ducks: The ducks are a regressive chain, each duck pulling the next, and in turn the baron along ad infinitum, suggesting no ultimate grounding only an endless line of ducks.
Hair Pulling: Baron Munchausen attempts to lift himself by his own hair, representing circular reasoning.
These three images represent the Münchhausen trilemma.
Fun fact. In statistics, we often use bootstrapping, where a single dataset is repeatedly resampled to provide estimates of the uncertainty/variance.
The idea that you can get reliable estimates of variance just by re-sampling the same data seem illogical, and the term bootstrap derives from the phrase to pull oneself up by one's bootstrap, widely thought to be based on one of the eighteenth century Adventures of Baron Munchausen, by Rudolph Erich Raspe. (The Baron had fallen to the bottom of a deep lake. Just when it looked like all was lost, he thought to pick himself up by his own bootstraps.)
There's also a bootstrap paradox, with events caused by themselves. E.g. going back in time to be your own parent.