Sidekick facts for kids
A sidekick is someone who regularly travels with, and helps, another person. In fiction, the other person is often a crimefighter or superhero, such as Batman and his sidekick Robin. Some people consider Sancho Panza, Don Quixote's ever-faithful companion, to be a type of sidekick, even though the book was written long before the word sidekick was invented.
Some well-known fictional sidekicks are Don Quixote's Sancho Panza, Sherlock Holmes' Doctor Watson, The Lone Ranger's Tonto, The Green Hornet's Kato, Shrek's Donkey (and sometimes Puss in Boots), Mickey Mouse's Donald Duck (and sometimes Goofy), Mario's Luigi, Sonic's Tails (& Knuckles), Donkey Kong's Diddy Kong, Daffy Duck's Porky Pig and Batman's Robin.
Sidekick Facts for Kids. Kiddle Encyclopedia.