Alternate:
Propellers on their hats
Current:
Flags on their hats
Crazy headgear - but what was it exactly?
Tweedledee and Tweedledum first appeared in a poem by John Byrom, but were made much more famous in Lewis Caroll's Through the Looking-Glass and what Alice Found There - which is of course better known as Alice in Wonderland.
In the Disney Movie of 1951, they clearly have yellow flags on their hats, yet many people remember them as having propellers. There are plenty of references to them on the internet today, including artwork and costumes. Alice in Wonderland is the subject of other MMDE's, which is hardly surprising given the craziness in her world...
None at all in the 1871 book
Here's how the hats looked in 1871: