Flaming flamingos flying free,
Fetching figures, flocking floaters,
Fishing for food, freshwater fare;
Fiery feathers, flapping forms,
Flaming Flamingos flying free.

Whew - that was tough but fun. Today's form is tautogram -  best explained by its Greek root words of "tauto" meaning "the same" and "gramma" meaning "letter." Basically, all words in the poem begin with the same letter.

I think we would call them tongue twisters, though this twisted by brains too. Hence the short poem and the 'cheating' by repeating the first line.