Rookie class is the term used which refers to the 3rd stage of Digimon evolution.
Child class are among the most popular and well-known.
This form is appealing because they are generally young enough to be considered cute and cuddly, while still having distinct designs and attack powers.
Their size also means that it is easier for them to fit into places larger Digimon would not be able to.
Digimon evolution begins to branch extensively at this point, with some Digimon having countless possible evolutions.