Tongue twisters or trabalenguas are phrases that use repetitive syllable sounds that make them difficult to pronounce but when practiced can improve your Spanish pronunciation.
Because of the rhymes, they are often used with children as a fun exercise to practice Spanish pronunciation and diction when learning the language at an early age. The objective of a tongue twister is to pronounce it clearly at a normal speed (or increasing the speed of speech) without any mistakes.
In a previous Speaking Latino article early this year, Spanish teacher and blogger Rease Kirchner, wrote about the good practice of using children materials when adults are learning a new language.
Trabalenguas are part of the oral literature and popular culture, that is why there are some many variations of the same ones. Some are considered classics that are known across countries. Others are particular to a specific country.