Obtaining this new Pokemon is not as easy as you might think. Here's our guide to evolving Marill and getting Azumarill.
Friendship Is Key!
Friendship is a mechanic within the Pokemon series that does not have an actual meter or gauge, but it is one of the most important measurements for some Pokemon.
In order to improve your Pokemon's friendship levels, all you have to do is keep the Pokemon in your party; and make sure you do not let your Pokemon faint. Over time, the Pokemon will gain more and more friendship although you may never know how high your friendship is.
To get Marill's final evolution form, Azumarill you are going to want to LVL up Marill to LVL 18. Then, once you keep levelling up Azumarill, if your friendship is high enough with Marill, it will evolve at some point!